rewrote singleton to enum where applicable

Mage.Client/src/main/java/mage/client/deckeditor/SortSettingBase.java

@@ -36,10 +36,10 @@ import mage.client.dialog.PreferencesDialog;
 
 public class SortSettingBase extends SortSetting {
 
-    private final static SortSettingBase fInstance = new SortSettingBase();
+    private final static SortSettingBase instance = new SortSettingBase();
 
     public static SortSettingBase getInstance() {
-        return fInstance;
+        return instance;
     }
 
     private SortSettingBase() {

Mage.Client/src/main/java/mage/client/deckeditor/SortSettingDeck.java

@@ -36,10 +36,10 @@ import mage.client.dialog.PreferencesDialog;
 
 public class SortSettingDeck extends SortSetting {
 
-    private final static SortSettingDeck fInstance = new SortSettingDeck();
+    private final static SortSettingDeck instance = new SortSettingDeck();
 
     public static SortSettingDeck getInstance() {
-        return fInstance;
+        return instance;
     }
 
     private SortSettingDeck() {

Mage.Client/src/main/java/mage/client/deckeditor/SortSettingDraft.java

@@ -36,10 +36,10 @@ import mage.client.dialog.PreferencesDialog;
  */
 public class SortSettingDraft extends SortSetting {
 
-    private final static SortSettingDraft fInstance = new SortSettingDraft();
+    private final static SortSettingDraft instance = new SortSettingDraft();
 
     public static SortSettingDraft getInstance() {
-        return fInstance;
+        return instance;
     }
 
     private SortSettingDraft() {

Mage.Client/src/main/java/mage/client/deckeditor/SortSettingSideboard.java

@@ -36,10 +36,10 @@ import mage.client.dialog.PreferencesDialog;
 
 public class SortSettingSideboard extends SortSetting {
 
-    private static final SortSettingSideboard fInstance = new SortSettingSideboard();
+    private static final SortSettingSideboard instance = new SortSettingSideboard();
 
     public static SortSettingSideboard getInstance() {
-        return fInstance;
+        return instance;
     }
 
     private SortSettingSideboard() {

Mage.Client/src/main/java/mage/client/plugins/impl/Plugins.java

@@ -35,7 +35,7 @@ public class Plugins implements MagePlugins {
 
     public static final String PLUGINS_DIRECTORY = "plugins/";
 
-    private static final MagePlugins fINSTANCE = new Plugins();
+    private static final MagePlugins instance = new Plugins();
     private static final Logger LOGGER = Logger.getLogger(Plugins.class);
     private static PluginManager pm;
 
@@ -46,7 +46,7 @@ public class Plugins implements MagePlugins {
     private final Map<String, String> sortingOptions = new HashMap<>();
 
     public static MagePlugins getInstance() {
-        return fINSTANCE;
+        return instance;
     }
 
     @Override

Mage.Client/src/main/java/mage/client/unusedFiles/DelayedViewerThread.java

@@ -9,10 +9,10 @@ import java.util.Map;
 
 
 public class DelayedViewerThread extends Thread {
-    private static final DelayedViewerThread fInstance = new DelayedViewerThread();
+    private static final DelayedViewerThread instance = new DelayedViewerThread();
 
     public static DelayedViewerThread getInstance() {
-        return fInstance;
+        return instance;
     }
 
     private final Map<Component, Long> delayedViewers;

Mage.Client/src/main/java/mage/client/util/GameManager.java

@@ -8,10 +8,10 @@ import java.util.UUID;
  * @author nantuko
  */
 public class GameManager {
-    private static final GameManager fInstance = new GameManager();
+    private static final GameManager instance = new GameManager();
 
     public static GameManager getInstance() {
-        return fInstance;
+        return instance;
     }
 
     public void setStackSize(int stackSize) {

Mage.Client/src/main/java/mage/client/util/SettingsManager.java

@@ -10,10 +10,10 @@ import org.mage.card.arcane.CardPanel;
  * @author nantuko
  */
 public class SettingsManager {
-    private static final SettingsManager fInstance = new SettingsManager();
+    private static final SettingsManager instance = new SettingsManager();
 
     public static SettingsManager getInstance() {
-        return fInstance;
+        return instance;
     }
 
     public int getScreenWidth() {

Mage.Client/src/main/java/org/mage/plugins/card/utils/impl/ImageManagerImpl.java

@@ -19,10 +19,10 @@ import org.mage.plugins.card.utils.Transparency;
 
 public class ImageManagerImpl implements ImageManager {
 
-    private static final ImageManagerImpl fInstance = new ImageManagerImpl();
+    private static final ImageManagerImpl instance = new ImageManagerImpl();
 
     public static ImageManagerImpl getInstance() {
-        return fInstance;
+        return instance;
     }
     
     public ImageManagerImpl() {

Mage.Server/src/main/java/mage/server/ChatManager.java

@@ -44,19 +44,12 @@ import java.util.regex.Pattern;
 /**
  * @author BetaSteward_at_googlemail.com
  */
-public class ChatManager {
+public enum ChatManager {
 
+    instance;
     private static final Logger logger = Logger.getLogger(ChatManager.class);
     private static final HashMap<String, String> userMessages = new HashMap<>();
 
-    private static final ChatManager INSTANCE = new ChatManager();
-
-    public static ChatManager getInstance() {
-        return INSTANCE;
-    }
-
-    private ChatManager() {
-    }
 
     private final ConcurrentHashMap<UUID, ChatSession> chatSessions = new ConcurrentHashMap<>();
 
@@ -113,7 +106,7 @@ public class ChatManager {
         ChatSession chatSession = chatSessions.get(chatId);
         if (chatSession != null) {
             if (message.startsWith("\\") || message.startsWith("/")) {
-                User user = UserManager.getInstance().getUserByName(userName);
+                User user = UserManager.instance.getUserByName(userName);
                 if (user != null) {
                     if (!performUserCommand(user, message, chatId, false)) {
                         performUserCommand(user, message, chatId, true);
@@ -123,7 +116,7 @@ public class ChatManager {
             }
 
             if (messageType != MessageType.GAME) {
-                User user = UserManager.getInstance().getUserByName(userName);
+                User user = UserManager.instance.getUserByName(userName);
                 if (message != null && userName != null && !userName.isEmpty()) {
 
                     if (message.equals(userMessages.get(userName))) {
@@ -205,12 +198,12 @@ public class ChatManager {
         }
 
         if (command.startsWith("H ") || command.startsWith("HISTORY ")) {
-            message += "<br/>" + UserManager.getInstance().getUserHistory(message.substring(command.startsWith("H ") ? 3 : 9));
+            message += "<br/>" + UserManager.instance.getUserHistory(message.substring(command.startsWith("H ") ? 3 : 9));
             chatSessions.get(chatId).broadcastInfoToUser(user, message);
             return true;
         }
         if (command.equals("ME")) {
-            message += "<br/>" + UserManager.getInstance().getUserHistory(user.getName());
+            message += "<br/>" + UserManager.instance.getUserHistory(user.getName());
             chatSessions.get(chatId).broadcastInfoToUser(user, message);
             return true;
         }
@@ -220,7 +213,7 @@ public class ChatManager {
             if (first > 1) {
                 String userToName = rest.substring(0, first);
                 rest = rest.substring(first + 1).trim();
-                User userTo = UserManager.getInstance().getUserByName(userToName);
+                User userTo = UserManager.instance.getUserByName(userToName);
                 if (userTo != null) {
                     if (!chatSessions.get(chatId).broadcastWhisperToUser(user, userTo, rest)) {
                         message += new StringBuilder("<br/>User ").append(userToName).append(" not found").toString();
@@ -251,7 +244,7 @@ public class ChatManager {
      * @param color
      */
     public void broadcast(UUID userId, String message, MessageColor color) throws UserNotFoundException {
-        UserManager.getInstance().getUser(userId).ifPresent(user-> {
+        UserManager.instance.getUser(userId).ifPresent(user-> {
             chatSessions.values()
                     .stream()
                     .filter(chat -> chat.hasUser(userId))
@@ -261,7 +254,7 @@ public class ChatManager {
     }
 
     public void sendReconnectMessage(UUID userId) {
-        UserManager.getInstance().getUser(userId).ifPresent(user ->
+        UserManager.instance.getUser(userId).ifPresent(user ->
                 chatSessions.values()
                         .stream()
                         .filter(chat -> chat.hasUser(userId))

Mage.Server/src/main/java/mage/server/ChatSession.java

@@ -61,7 +61,7 @@ public class ChatSession {
     }
 
     public void join(UUID userId) {
-       UserManager.getInstance().getUser(userId).ifPresent(user-> {
+       UserManager.instance.getUser(userId).ifPresent(user-> {
            if (!clients.containsKey(userId)) {
                String userName = user.getName();
                clients.put(userId, userName);
@@ -142,7 +142,7 @@ public class ChatSession {
             HashSet<UUID> clientsToRemove = null;
             ClientCallback clientCallback = new ClientCallback("chatMessage", chatId, new ChatMessage(userName, message, (withTime ? timeFormatter.format(new Date()) : ""), color, messageType, soundToPlay));
             for (UUID userId : clients.keySet()) {
-                Optional<User> user = UserManager.getInstance().getUser(userId);
+                Optional<User> user = UserManager.instance.getUser(userId);
                 if (user.isPresent()) {
                     user.get().fireCallback(clientCallback);
                 } else {

Mage.Server/src/main/java/mage/server/GmailClient.java

@@ -80,8 +80,8 @@ public final class GmailClient {
             Message message = new Message();
             message.setRaw(Base64.encodeBase64URLSafeString(baos.toByteArray()));
 
-            gmail.users().messages().send(ConfigSettings.getInstance().getGoogleAccount()
+            gmail.users().messages().send(ConfigSettings.instance.getGoogleAccount()
-                    + (ConfigSettings.getInstance().getGoogleAccount().endsWith("@gmail.com") ? "" : "@gmail.com"), message).execute();
+                    + (ConfigSettings.instance.getGoogleAccount().endsWith("@gmail.com") ? "" : "@gmail.com"), message).execute();
             return true;
         } catch (MessagingException | IOException ex) {
             logger.error("Error sending message", ex);

Mage.Server/src/main/java/mage/server/MageServerImpl.java

@@ -90,12 +90,12 @@ public class MageServerImpl implements MageServer {
     public MageServerImpl(String adminPassword, boolean testMode) {
         this.adminPassword = adminPassword;
         this.testMode = testMode;
-        ServerMessagesUtil.getInstance().getMessages();
+        ServerMessagesUtil.instance.getMessages();
     }
 
     @Override
     public boolean registerUser(String sessionId, String userName, String password, String email) throws MageException {
-        return SessionManager.getInstance().registerUser(sessionId, userName, password, email);
+        return SessionManager.instance.registerUser(sessionId, userName, password, email);
     }
 
     // generateAuthToken returns a uniformly distributed 6-digits string.
@@ -105,7 +105,7 @@ public class MageServerImpl implements MageServer {
 
     @Override
     public boolean emailAuthToken(String sessionId, String email) throws MageException {
-        if (!ConfigSettings.getInstance().isAuthenticationActivated()) {
+        if (!ConfigSettings.instance.isAuthenticationActivated()) {
             sendErrorMessageToClient(sessionId, "Registration is disabled by the server config");
             return false;
         }
@@ -121,7 +121,7 @@ public class MageServerImpl implements MageServer {
         String text = "Use this auth token to reset " + authorizedUser.name + "'s password: " + authToken + '\n'
                 + "It's valid until the next server restart.";
         boolean success;
-        if (!ConfigSettings.getInstance().getMailUser().isEmpty()) {
+        if (!ConfigSettings.instance.getMailUser().isEmpty()) {
             success = MailClient.sendMessage(email, subject, text);
         } else {
             success = MailgunClient.sendMessage(email, subject, text);
@@ -135,7 +135,7 @@ public class MageServerImpl implements MageServer {
 
     @Override
     public boolean resetPassword(String sessionId, String email, String authToken, String password) throws MageException {
-        if (!ConfigSettings.getInstance().isAuthenticationActivated()) {
+        if (!ConfigSettings.instance.isAuthenticationActivated()) {
             sendErrorMessageToClient(sessionId, "Registration is disabled by the server config");
             return false;
         }
@@ -164,7 +164,7 @@ public class MageServerImpl implements MageServer {
                 logger.info("MageVersionException: userName=" + userName + ", version=" + version);
                 throw new MageVersionException(version, Main.getVersion());
             }
-            return SessionManager.getInstance().connectUser(sessionId, userName, password, userIdStr);
+            return SessionManager.instance.connectUser(sessionId, userName, password, userIdStr);
         } catch (MageException ex) {
             if (ex instanceof MageVersionException) {
                 throw (MageVersionException) ex;
@@ -179,7 +179,7 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("setUserData", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() throws MageException {
-                return SessionManager.getInstance().setUserData(userName, sessionId, userData, clientVersion, userIdStr);
+                return SessionManager.instance.setUserData(userName, sessionId, userData, clientVersion, userIdStr);
             }
         });
     }
@@ -193,7 +193,7 @@ public class MageServerImpl implements MageServer {
             if (!adminPassword.equals(this.adminPassword)) {
                 throw new MageException("Wrong password");
             }
-            return SessionManager.getInstance().connectAdmin(sessionId);
+            return SessionManager.instance.connectAdmin(sessionId);
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -211,8 +211,8 @@ public class MageServerImpl implements MageServer {
             @Override
             public TableView execute() throws MageException {
                 try {
-                    UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                    UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                    Optional<User> _user = UserManager.getInstance().getUser(userId);
+                    Optional<User> _user = UserManager.instance.getUser(userId);
                     if (!_user.isPresent()) {
                         logger.error("User for session not found. session = " + sessionId);
                         return null;
@@ -225,7 +225,7 @@ public class MageServerImpl implements MageServer {
                         throw new MageException("No message");
                     }
                     // check AI players max
-                    String maxAiOpponents = ConfigSettings.getInstance().getMaxAiOpponents();
+                    String maxAiOpponents = ConfigSettings.instance.getMaxAiOpponents();
                     if (maxAiOpponents != null) {
                         int aiPlayers = 0;
                         for (String playerType : options.getPlayerTypes()) {
@@ -247,7 +247,7 @@ public class MageServerImpl implements MageServer {
                         user.showUserMessage("Create tournament", message);
                         throw new MageException("No message");
                     }
-                    TableView table = GamesRoomManager.getInstance().getRoom(roomId).createTournamentTable(userId, options);
+                    TableView table = GamesRoomManager.instance.getRoom(roomId).createTournamentTable(userId, options);
                     logger.debug("Tournament table " + table.getTableId() + " created");
                     return table;
                 } catch (Exception ex) {
@@ -261,8 +261,8 @@ public class MageServerImpl implements MageServer {
     @Override
     public void removeTable(final String sessionId, final UUID roomId, final UUID tableId) throws MageException {
         execute("removeTable", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().removeTable(userId, tableId);
+            TableManager.instance.removeTable(userId, tableId);
         });
     }
 
@@ -271,13 +271,13 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("joinTable", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() throws MageException {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
                 logger.debug(name + " joins tableId: " + tableId);
                 if (userId == null) {
                     logger.fatal("Got no userId from sessionId" + sessionId + " tableId" + tableId);
                     return false;
                 }
-                return GamesRoomManager.getInstance().getRoom(roomId).joinTable(userId, tableId, name, playerType, skill, deckList, password);
+                return GamesRoomManager.instance.getRoom(roomId).joinTable(userId, tableId, name, playerType, skill, deckList, password);
 
             }
         });
@@ -288,16 +288,16 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("joinTournamentTable", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() throws MageException {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
                 if (logger.isTraceEnabled()) {
-                    Optional<User> user = UserManager.getInstance().getUser(userId);
+                    Optional<User> user = UserManager.instance.getUser(userId);
                     user.ifPresent(user1 -> logger.trace("join tourn. tableId: " + tableId + ' ' + name));
                 }
                 if (userId == null) {
                     logger.fatal("Got no userId from sessionId" + sessionId + " tableId" + tableId);
                     return false;
                 }
-                return GamesRoomManager.getInstance().getRoom(roomId).joinTournamentTable(userId, tableId, name, playerType, skill, deckList, password);
+                return GamesRoomManager.instance.getRoom(roomId).joinTournamentTable(userId, tableId, name, playerType, skill, deckList, password);
 
             }
         });
@@ -308,8 +308,8 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("submitDeck", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() throws MageException {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                boolean ret = TableManager.getInstance().submitDeck(userId, tableId, deckList);
+                boolean ret = TableManager.instance.submitDeck(userId, tableId, deckList);
                 logger.debug("Session " + sessionId + " submitted deck");
                 return ret;
             }
@@ -319,8 +319,8 @@ public class MageServerImpl implements MageServer {
     @Override
     public void updateDeck(final String sessionId, final UUID tableId, final DeckCardLists deckList) throws MageException, GameException {
         execute("updateDeck", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().updateDeck(userId, tableId, deckList);
+            TableManager.instance.updateDeck(userId, tableId, deckList);
             logger.trace("Session " + sessionId + " updated deck");
         });
     }
@@ -329,7 +329,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public List<TableView> getTables(UUID roomId) throws MageException {
         try {
-            GamesRoom room = GamesRoomManager.getInstance().getRoom(roomId);
+            GamesRoom room = GamesRoomManager.instance.getRoom(roomId);
             if (room != null) {
                 return room.getTables();
             } else {
@@ -345,7 +345,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public List<MatchView> getFinishedMatches(UUID roomId) throws MageException {
         try {
-            GamesRoom room = GamesRoomManager.getInstance().getRoom(roomId);
+            GamesRoom room = GamesRoomManager.instance.getRoom(roomId);
             if (room != null) {
                 return room.getFinished();
             } else {
@@ -360,7 +360,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public List<RoomUsersView> getRoomUsers(UUID roomId) throws MageException {
         try {
-            GamesRoom room = GamesRoomManager.getInstance().getRoom(roomId);
+            GamesRoom room = GamesRoomManager.instance.getRoom(roomId);
             if (room != null) {
                 return room.getRoomUsersInfo();
             } else {
@@ -376,7 +376,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public TableView getTable(UUID roomId, UUID tableId) throws MageException {
         try {
-            GamesRoom room = GamesRoomManager.getInstance().getRoom(roomId);
+            GamesRoom room = GamesRoomManager.instance.getRoom(roomId);
             if (room != null) {
                 return room.getTable(tableId);
             } else {
@@ -390,7 +390,7 @@ public class MageServerImpl implements MageServer {
 
     @Override
     public boolean ping(String sessionId, String pingInfo) {
-        return SessionManager.getInstance().extendUserSession(sessionId, pingInfo);
+        return SessionManager.instance.extendUserSession(sessionId, pingInfo);
     }
 
     //    @Override
@@ -398,19 +398,19 @@ public class MageServerImpl implements MageServer {
 //        execute("deregisterClient", sessionId, new Action() {
 //            @Override
 //            public void execute() {
-//                SessionManager.getInstance().disconnect(sessionId, true);
+//                SessionManager.instance.disconnect(sessionId, true);
 //                logger.debug("Client deregistered ...");
 //            }
 //        });
 //    }
     @Override
     public boolean startMatch(final String sessionId, final UUID roomId, final UUID tableId) throws MageException {
-        if (!TableManager.getInstance().getController(tableId).changeTableStateToStarting()) {
+        if (!TableManager.instance.getController(tableId).changeTableStateToStarting()) {
             return false;
         }
         execute("startMatch", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().startMatch(userId, roomId, tableId);
+            TableManager.instance.startMatch(userId, roomId, tableId);
         });
         return true;
     }
@@ -420,19 +420,19 @@ public class MageServerImpl implements MageServer {
 //        execute("startChallenge", sessionId, new Action() {
 //            @Override
 //            public void execute() {
-//                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+//                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-//                TableManager.getInstance().startChallenge(userId, roomId, tableId, challengeId);
+//                TableManager.instance.startChallenge(userId, roomId, tableId, challengeId);
 //            }
 //        });
 //    }
     @Override
     public boolean startTournament(final String sessionId, final UUID roomId, final UUID tableId) throws MageException {
-        if (!TableManager.getInstance().getController(tableId).changeTableStateToStarting()) {
+        if (!TableManager.instance.getController(tableId).changeTableStateToStarting()) {
             return false;
         }
         execute("startTournament", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().startTournament(userId, roomId, tableId);
+            TableManager.instance.startTournament(userId, roomId, tableId);
         });
         return true;
     }
@@ -441,7 +441,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public TournamentView getTournament(UUID tournamentId) throws MageException {
         try {
-            return TournamentManager.getInstance().getTournamentView(tournamentId);
+            return TournamentManager.instance.getTournamentView(tournamentId);
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -453,7 +453,7 @@ public class MageServerImpl implements MageServer {
     public void sendChatMessage(final UUID chatId, final String userName, final String message) throws MageException {
         try {
             callExecutor.execute(
-                    () -> ChatManager.getInstance().broadcast(chatId, userName, StringEscapeUtils.escapeHtml4(message), MessageColor.BLUE, true, ChatMessage.MessageType.TALK, null)
+                    () -> ChatManager.instance.broadcast(chatId, userName, StringEscapeUtils.escapeHtml4(message), MessageColor.BLUE, true, ChatMessage.MessageType.TALK, null)
             );
         } catch (Exception ex) {
             handleException(ex);
@@ -463,8 +463,8 @@ public class MageServerImpl implements MageServer {
     @Override
     public void joinChat(final UUID chatId, final String sessionId, final String userName) throws MageException {
         execute("joinChat", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ChatManager.getInstance().joinChat(chatId, userId);
+            ChatManager.instance.joinChat(chatId, userId);
         });
     }
 
@@ -472,8 +472,8 @@ public class MageServerImpl implements MageServer {
     public void leaveChat(final UUID chatId, final String sessionId) throws MageException {
         execute("leaveChat", sessionId, () -> {
             if (chatId != null) {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                ChatManager.getInstance().leaveChat(chatId, userId);
+                ChatManager.instance.leaveChat(chatId, userId);
             } else {
                 logger.warn("The chatId is null.  sessionId = " + sessionId);
             }
@@ -484,7 +484,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public UUID getMainRoomId() throws MageException {
         try {
-            return GamesRoomManager.getInstance().getMainRoomId();
+            return GamesRoomManager.instance.getMainRoomId();
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -495,7 +495,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public UUID getRoomChatId(UUID roomId) throws MageException {
         try {
-            return GamesRoomManager.getInstance().getRoom(roomId).getChatId();
+            return GamesRoomManager.instance.getRoom(roomId).getChatId();
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -507,8 +507,8 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("isTableOwner", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                return TableManager.getInstance().isTableOwner(tableId, userId);
+                return TableManager.instance.isTableOwner(tableId, userId);
             }
         });
     }
@@ -516,21 +516,21 @@ public class MageServerImpl implements MageServer {
     @Override
     public void swapSeats(final String sessionId, final UUID roomId, final UUID tableId, final int seatNum1, final int seatNum2) throws MageException {
         execute("swapSeats", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().swapSeats(tableId, userId, seatNum1, seatNum2);
+            TableManager.instance.swapSeats(tableId, userId, seatNum1, seatNum2);
         });
     }
 
     @Override
     public boolean leaveTable(final String sessionId, final UUID roomId, final UUID tableId) throws MageException {
-        TableState tableState = TableManager.getInstance().getController(tableId).getTableState();
+        TableState tableState = TableManager.instance.getController(tableId).getTableState();
         if (tableState != TableState.WAITING && tableState != TableState.READY_TO_START) {
             // table was already started, so player can't leave anymore now
             return false;
         }
         execute("leaveTable", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            GamesRoomManager.getInstance().getRoom(roomId).leaveTable(userId, tableId);
+            GamesRoomManager.instance.getRoom(roomId).leaveTable(userId, tableId);
         });
         return true;
     }
@@ -539,7 +539,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public UUID getTableChatId(UUID tableId) throws MageException {
         try {
-            return TableManager.getInstance().getChatId(tableId);
+            return TableManager.instance.getChatId(tableId);
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -549,24 +549,24 @@ public class MageServerImpl implements MageServer {
     @Override
     public void joinGame(final UUID gameId, final String sessionId) throws MageException {
         execute("joinGame", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            GameManager.getInstance().joinGame(gameId, userId);
+            GameManager.instance.joinGame(gameId, userId);
         });
     }
 
     @Override
     public void joinDraft(final UUID draftId, final String sessionId) throws MageException {
         execute("joinDraft", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            DraftManager.getInstance().joinDraft(draftId, userId);
+            DraftManager.instance.joinDraft(draftId, userId);
         });
     }
 
     @Override
     public void joinTournament(final UUID tournamentId, final String sessionId) throws MageException {
         execute("joinTournament", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TournamentManager.getInstance().joinTournament(tournamentId, userId);
+            TournamentManager.instance.joinTournament(tournamentId, userId);
         });
     }
 
@@ -574,7 +574,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public UUID getGameChatId(UUID gameId) throws MageException {
         try {
-            return GameManager.getInstance().getChatId(gameId);
+            return GameManager.instance.getChatId(gameId);
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -585,7 +585,7 @@ public class MageServerImpl implements MageServer {
     //FIXME: why no sessionId here???
     public UUID getTournamentChatId(UUID tournamentId) throws MageException {
         try {
-            return TournamentManager.getInstance().getChatId(tournamentId);
+            return TournamentManager.instance.getChatId(tournamentId);
         } catch (Exception ex) {
             handleException(ex);
         }
@@ -595,7 +595,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerUUID(final UUID gameId, final String sessionId, final UUID data) throws MageException {
         execute("sendPlayerUUID", sessionId, () -> {
-            Optional<User> user = SessionManager.getInstance().getUser(sessionId);
+            Optional<User> user = SessionManager.instance.getUser(sessionId);
             if (user.isPresent()) {
 //                    logger.warn("sendPlayerUUID gameId=" + gameId + " sessionId=" + sessionId + " username=" + user.getName());
                 user.get().sendPlayerUUID(gameId, data);
@@ -608,7 +608,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerString(final UUID gameId, final String sessionId, final String data) throws MageException {
         execute("sendPlayerString", sessionId, () -> {
-            Optional<User> user = SessionManager.getInstance().getUser(sessionId);
+            Optional<User> user = SessionManager.instance.getUser(sessionId);
             if (user.isPresent()) {
                 user.get().sendPlayerString(gameId, data);
             } else {
@@ -620,7 +620,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerManaType(final UUID gameId, final UUID playerId, final String sessionId, final ManaType data) throws MageException {
         execute("sendPlayerManaType", sessionId, () -> {
-            Optional<User> user = SessionManager.getInstance().getUser(sessionId);
+            Optional<User> user = SessionManager.instance.getUser(sessionId);
             if (user.isPresent()) {
                 user.get().sendPlayerManaType(gameId, playerId, data);
             } else {
@@ -632,7 +632,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerBoolean(final UUID gameId, final String sessionId, final Boolean data) throws MageException {
         execute("sendPlayerBoolean", sessionId, () -> {
-            Optional<User> user = SessionManager.getInstance().getUser(sessionId);
+            Optional<User> user = SessionManager.instance.getUser(sessionId);
             if (user.isPresent()) {
                 user.get().sendPlayerBoolean(gameId, data);
             } else {
@@ -644,7 +644,7 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerInteger(final UUID gameId, final String sessionId, final Integer data) throws MageException {
         execute("sendPlayerInteger", sessionId, () -> {
-            Optional<User> user = SessionManager.getInstance().getUser(sessionId);
+            Optional<User> user = SessionManager.instance.getUser(sessionId);
             if (user.isPresent()) {
                 user.get().sendPlayerInteger(gameId, data);
             } else {
@@ -661,9 +661,9 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendCardMark(final UUID draftId, final String sessionId, final UUID cardPick) throws MageException {
         execute("sendCardMark", sessionId, () -> {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session != null) {
-                DraftManager.getInstance().sendCardMark(draftId, session.getUserId(), cardPick);
+                DraftManager.instance.sendCardMark(draftId, session.getUserId(), cardPick);
             } else {
                 logger.error("Session not found sessionId: " + sessionId + "  draftId:" + draftId);
             }
@@ -673,9 +673,9 @@ public class MageServerImpl implements MageServer {
     @Override
     public void quitMatch(final UUID gameId, final String sessionId) throws MageException {
         execute("quitMatch", sessionId, () -> {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session != null) {
-                GameManager.getInstance().quitMatch(gameId, session.getUserId());
+                GameManager.instance.quitMatch(gameId, session.getUserId());
             } else {
                 logger.error("Session not found sessionId: " + sessionId + "  gameId:" + gameId);
             }
@@ -685,9 +685,9 @@ public class MageServerImpl implements MageServer {
     @Override
     public void quitTournament(final UUID tournamentId, final String sessionId) throws MageException {
         execute("quitTournament", sessionId, () -> {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session != null) {
-                TournamentManager.getInstance().quit(tournamentId, session.getUserId());
+                TournamentManager.instance.quit(tournamentId, session.getUserId());
             } else {
                 logger.error("Session not found sessionId: " + sessionId + "  tournamentId:" + tournamentId);
             }
@@ -697,16 +697,16 @@ public class MageServerImpl implements MageServer {
     @Override
     public void quitDraft(final UUID draftId, final String sessionId) throws MageException {
         execute("quitDraft", sessionId, () -> {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session == null) {
                 logger.error("Session not found sessionId: " + sessionId + "  draftId:" + draftId);
                 return;
             }
-            UUID tableId = DraftManager.getInstance().getControllerByDraftId(draftId).getTableId();
+            UUID tableId = DraftManager.instance.getControllerByDraftId(draftId).getTableId();
-            Table table = TableManager.getInstance().getTable(tableId);
+            Table table = TableManager.instance.getTable(tableId);
             if (table.isTournament()) {
                 UUID tournamentId = table.getTournament().getId();
-                TournamentManager.getInstance().quit(tournamentId, session.getUserId());
+                TournamentManager.instance.quit(tournamentId, session.getUserId());
             }
         });
     }
@@ -714,12 +714,12 @@ public class MageServerImpl implements MageServer {
     @Override
     public void sendPlayerAction(final PlayerAction playerAction, final UUID gameId, final String sessionId, final Object data) throws MageException {
         execute("sendPlayerAction", sessionId, () -> {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session == null) {
                 logger.error("Session not found sessionId: " + sessionId + "  gameId:" + gameId);
                 return;
             }
-            GameManager.getInstance().sendPlayerAction(playerAction, gameId, session.getUserId(), data);
+            GameManager.instance.sendPlayerAction(playerAction, gameId, session.getUserId(), data);
         });
     }
 
@@ -728,8 +728,8 @@ public class MageServerImpl implements MageServer {
         return executeWithResult("setUserData", sessionId, new ActionWithBooleanResult() {
             @Override
             public Boolean execute() throws MageException {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                return GamesRoomManager.getInstance().getRoom(roomId).watchTable(userId, tableId);
+                return GamesRoomManager.instance.getRoom(roomId).watchTable(userId, tableId);
             }
         });
     }
@@ -742,17 +742,17 @@ public class MageServerImpl implements MageServer {
     @Override
     public void watchGame(final UUID gameId, final String sessionId) throws MageException {
         execute("watchGame", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            GameManager.getInstance().watchGame(gameId, userId);
+            GameManager.instance.watchGame(gameId, userId);
         });
     }
 
     @Override
     public void stopWatching(final UUID gameId, final String sessionId) throws MageException {
         execute("stopWatching", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            UserManager.getInstance().getUser(userId).ifPresent(user -> {
+            UserManager.instance.getUser(userId).ifPresent(user -> {
-                GameManager.getInstance().stopWatching(gameId, userId);
+                GameManager.instance.stopWatching(gameId, userId);
                 user.removeGameWatchInfo(gameId);
             });
 
@@ -762,48 +762,48 @@ public class MageServerImpl implements MageServer {
     @Override
     public void replayGame(final UUID gameId, final String sessionId) throws MageException {
         execute("replayGame", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().replayGame(gameId, userId);
+            ReplayManager.instance.replayGame(gameId, userId);
         });
     }
 
     @Override
     public void startReplay(final UUID gameId, final String sessionId) throws MageException {
         execute("startReplay", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().startReplay(gameId, userId);
+            ReplayManager.instance.startReplay(gameId, userId);
         });
     }
 
     @Override
     public void stopReplay(final UUID gameId, final String sessionId) throws MageException {
         execute("stopReplay", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().stopReplay(gameId, userId);
+            ReplayManager.instance.stopReplay(gameId, userId);
         });
     }
 
     @Override
     public void nextPlay(final UUID gameId, final String sessionId) throws MageException {
         execute("nextPlay", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().nextPlay(gameId, userId);
+            ReplayManager.instance.nextPlay(gameId, userId);
         });
     }
 
     @Override
     public void previousPlay(final UUID gameId, final String sessionId) throws MageException {
         execute("previousPlay", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().previousPlay(gameId, userId);
+            ReplayManager.instance.previousPlay(gameId, userId);
         });
     }
 
     @Override
     public void skipForward(final UUID gameId, final String sessionId, final int moves) throws MageException {
         execute("skipForward", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            ReplayManager.getInstance().skipForward(gameId, userId, moves);
+            ReplayManager.instance.skipForward(gameId, userId, moves);
         });
     }
 
@@ -832,8 +832,8 @@ public class MageServerImpl implements MageServer {
     public void cheat(final UUID gameId, final String sessionId, final UUID playerId, final DeckCardLists deckList) throws MageException {
         execute("cheat", sessionId, () -> {
             if (testMode) {
-                UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                GameManager.getInstance().cheat(gameId, userId, playerId, deckList);
+                GameManager.instance.cheat(gameId, userId, playerId, deckList);
             }
         });
     }
@@ -844,8 +844,8 @@ public class MageServerImpl implements MageServer {
             @Override
             public Boolean execute() {
                 if (testMode) {
-                    UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+                    UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-                    return GameManager.getInstance().cheat(gameId, userId, playerId, cardName);
+                    return GameManager.instance.cheat(gameId, userId, playerId, cardName);
                 }
                 return false;
             }
@@ -878,13 +878,13 @@ public class MageServerImpl implements MageServer {
 
     @Override
     public void disconnectUser(final String sessionId, final String userSessionId) throws MageException {
-        execute("disconnectUser", sessionId, () -> SessionManager.getInstance().disconnectUser(sessionId, userSessionId));
+        execute("disconnectUser", sessionId, () -> SessionManager.instance.disconnectUser(sessionId, userSessionId));
     }
 
     @Override
     public void muteUser(final String sessionId, final String userName, final long durationMinutes) throws MageException {
         execute("muteUser", sessionId, () -> {
-            User user = UserManager.getInstance().getUserByName(userName);
+            User user = UserManager.instance.getUserByName(userName);
             if (user != null) {
                 Date muteUntil = new Date(Calendar.getInstance().getTimeInMillis() + (durationMinutes * Timer.ONE_MINUTE));
                 user.showUserMessage("Admin info", "You were muted for chat messages until " + SystemUtil.dateFormat.format(muteUntil) + '.');
@@ -897,13 +897,13 @@ public class MageServerImpl implements MageServer {
     @Override
     public void lockUser(final String sessionId, final String userName, final long durationMinutes) throws MageException {
         execute("lockUser", sessionId, () -> {
-            User user = UserManager.getInstance().getUserByName(userName);
+            User user = UserManager.instance.getUserByName(userName);
             if (user != null) {
                 Date lockUntil = new Date(Calendar.getInstance().getTimeInMillis() + (durationMinutes * Timer.ONE_MINUTE));
                 user.showUserMessage("Admin info", "Your user profile was locked until " + SystemUtil.dateFormat.format(lockUntil) + '.');
                 user.setLockedUntil(lockUntil);
                 if (user.isConnected()) {
-                    SessionManager.getInstance().disconnectUser(sessionId, user.getSessionId());
+                    SessionManager.instance.disconnectUser(sessionId, user.getSessionId());
                 }
             }
 
@@ -914,11 +914,11 @@ public class MageServerImpl implements MageServer {
     public void setActivation(final String sessionId, final String userName, boolean active) throws MageException {
         execute("setActivation", sessionId, () -> {
             AuthorizedUser authorizedUser = AuthorizedUserRepository.instance.getByName(userName);
-            User user = UserManager.getInstance().getUserByName(userName);
+            User user = UserManager.instance.getUserByName(userName);
             if (user != null) {
                 user.setActive(active);
                 if (!user.isActive() && user.isConnected()) {
-                    SessionManager.getInstance().disconnectUser(sessionId, user.getSessionId());
+                    SessionManager.instance.disconnectUser(sessionId, user.getSessionId());
                 }
             } else if (authorizedUser != null) {
                 User theUser = new User(userName, "localhost", authorizedUser);
@@ -931,11 +931,11 @@ public class MageServerImpl implements MageServer {
     @Override
     public void toggleActivation(final String sessionId, final String userName) throws MageException {
         execute("toggleActivation", sessionId, () -> {
-            User user = UserManager.getInstance().getUserByName(userName);
+            User user = UserManager.instance.getUserByName(userName);
             if (user != null) {
                 user.setActive(!user.isActive());
                 if (!user.isActive() && user.isConnected()) {
-                    SessionManager.getInstance().disconnectUser(sessionId, user.getSessionId());
+                    SessionManager.instance.disconnectUser(sessionId, user.getSessionId());
                 }
             }
 
@@ -944,7 +944,7 @@ public class MageServerImpl implements MageServer {
 
     @Override
     public void endUserSession(final String sessionId, final String userSessionId) throws MageException {
-        execute("endUserSession", sessionId, () -> SessionManager.getInstance().endUserSession(sessionId, userSessionId));
+        execute("endUserSession", sessionId, () -> SessionManager.instance.endUserSession(sessionId, userSessionId));
     }
 
     /**
@@ -957,8 +957,8 @@ public class MageServerImpl implements MageServer {
     @Override
     public void removeTable(final String sessionId, final UUID tableId) throws MageException {
         execute("removeTable", sessionId, () -> {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            TableManager.getInstance().removeTable(userId, tableId);
+            TableManager.instance.removeTable(userId, tableId);
         });
     }
 
@@ -971,7 +971,7 @@ public class MageServerImpl implements MageServer {
     public void sendFeedbackMessage(final String sessionId, final String username, final String title, final String type, final String message, final String email) throws MageException {
         if (title != null && message != null) {
             execute("sendFeedbackMessage", sessionId, () -> {
-                String host = SessionManager.getInstance().getSession(sessionId).getHost();
+                String host = SessionManager.instance.getSession(sessionId).getHost();
                 FeedbackServiceImpl.instance.feedback(username, title, type, message, email, host);
             });
         }
@@ -981,7 +981,7 @@ public class MageServerImpl implements MageServer {
     public void sendBroadcastMessage(final String sessionId, final String message) throws MageException {
         if (message != null) {
             execute("sendBroadcastMessage", sessionId, () -> {
-                for (User user : UserManager.getInstance().getUsers()) {
+                for (User user : UserManager.instance.getUsers()) {
                     if (message.toLowerCase(Locale.ENGLISH).startsWith("warn")) {
                         user.fireCallback(new ClientCallback("serverMessage", null, new ChatMessage("SERVER", message, null, MessageColor.RED)));
                     } else {
@@ -993,12 +993,12 @@ public class MageServerImpl implements MageServer {
     }
 
     private void sendErrorMessageToClient(final String sessionId, final String message) throws MageException {
-        execute("sendErrorMessageToClient", sessionId, () -> SessionManager.getInstance().sendErrorMessageToClient(sessionId, message));
+        execute("sendErrorMessageToClient", sessionId, () -> SessionManager.instance.sendErrorMessageToClient(sessionId, message));
     }
 
     protected void execute(final String actionName, final String sessionId, final Action action, boolean checkAdminRights) throws MageException {
         if (checkAdminRights) {
-            if (!SessionManager.getInstance().isAdmin(sessionId)) {
+            if (!SessionManager.instance.isAdmin(sessionId)) {
                 return;
             }
         }
@@ -1006,11 +1006,11 @@ public class MageServerImpl implements MageServer {
     }
 
     protected void execute(final String actionName, final String sessionId, final Action action) throws MageException {
-        if (SessionManager.getInstance().isValidSession(sessionId)) {
+        if (SessionManager.instance.isValidSession(sessionId)) {
             try {
                 callExecutor.execute(
                         () -> {
-                            if (SessionManager.getInstance().isValidSession(sessionId)) {
+                            if (SessionManager.instance.isValidSession(sessionId)) {
                                 try {
                                     action.execute();
                                 } catch (MageException me) {
@@ -1027,7 +1027,7 @@ public class MageServerImpl implements MageServer {
 
     protected <T> T executeWithResult(String actionName, final String sessionId, final ActionWithResult<T> action, boolean checkAdminRights) throws MageException {
         if (checkAdminRights) {
-            if (!SessionManager.getInstance().isAdmin(sessionId)) {
+            if (!SessionManager.instance.isAdmin(sessionId)) {
                 return action.negativeResult();
             }
         }
@@ -1036,7 +1036,7 @@ public class MageServerImpl implements MageServer {
 
     //TODO: also run in threads with future task
     protected <T> T executeWithResult(String actionName, final String sessionId, final ActionWithResult<T> action) throws MageException {
-        if (SessionManager.getInstance().isValidSession(sessionId)) {
+        if (SessionManager.instance.isValidSession(sessionId)) {
             try {
                 return action.execute();
             } catch (Exception ex) {
@@ -1065,7 +1065,7 @@ public class MageServerImpl implements MageServer {
     private static class MyActionWithNullNegativeResult extends ActionWithNullNegativeResult<Object> {
         @Override
         public Object execute() throws MageException {
-            return CompressUtil.compress(ServerMessagesUtil.getInstance().getMessages());
+            return CompressUtil.compress(ServerMessagesUtil.instance.getMessages());
         }
     }
 
@@ -1073,7 +1073,7 @@ public class MageServerImpl implements MageServer {
         @Override
         public List<UserView> execute() throws MageException {
             List<UserView> users = new ArrayList<>();
-            for (User user : UserManager.getInstance().getUsers()) {
+            for (User user : UserManager.instance.getUsers()) {
                 users.add(new UserView(
                         user.getName(),
                         user.getHost(),
@@ -1104,8 +1104,8 @@ public class MageServerImpl implements MageServer {
 
         @Override
         public GameView execute() throws MageException {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            return GameManager.getInstance().getGameView(gameId, userId, playerId);
+            return GameManager.instance.getGameView(gameId, userId, playerId);
         }
     }
 
@@ -1120,8 +1120,8 @@ public class MageServerImpl implements MageServer {
 
         @Override
         public Boolean execute() throws MageException {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            return TableManager.getInstance().watchTable(userId, tableId);
+            return TableManager.instance.watchTable(userId, tableId);
         }
     }
 
@@ -1140,9 +1140,9 @@ public class MageServerImpl implements MageServer {
 
         @Override
         public DraftPickView execute() {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session != null) {
-                return DraftManager.getInstance().sendCardPick(draftId, session.getUserId(), cardPick, hiddenCards);
+                return DraftManager.instance.sendCardPick(draftId, session.getUserId(), cardPick, hiddenCards);
             } else {
                 logger.error("Session not found sessionId: " + sessionId + "  draftId:" + draftId);
             }
@@ -1163,8 +1163,8 @@ public class MageServerImpl implements MageServer {
 
         @Override
         public TableView execute() throws MageException {
-            UUID userId = SessionManager.getInstance().getSession(sessionId).getUserId();
+            UUID userId = SessionManager.instance.getSession(sessionId).getUserId();
-            Optional<User> _user = UserManager.getInstance().getUser(userId);
+            Optional<User> _user = UserManager.instance.getUser(userId);
             if (!_user.isPresent()) {
                 logger.error("User for session not found. session = " + sessionId);
                 return null;
@@ -1183,11 +1183,11 @@ public class MageServerImpl implements MageServer {
                 throw new MageException("No message");
             }
 
-            TableView table = GamesRoomManager.getInstance().getRoom(roomId).createTable(userId, options);
+            TableView table = GamesRoomManager.instance.getRoom(roomId).createTable(userId, options);
             if (logger.isDebugEnabled()) {
                 logger.debug("TABLE created - tableId: " + table.getTableId() + ' ' + table.getTableName());
                 logger.debug("- " + user.getName() + " userId: " + user.getId());
-                logger.debug("- chatId: " + TableManager.getInstance().getChatId(table.getTableId()));
+                logger.debug("- chatId: " + TableManager.instance.getChatId(table.getTableId()));
             }
             return table;
         }

Mage.Server/src/main/java/mage/server/MailClient.java

@@ -19,7 +19,7 @@ public final class MailClient {
             logger.info("Email is not sent because the address is empty");
             return false;
         }
-        ConfigSettings config = ConfigSettings.getInstance();
+        ConfigSettings config = ConfigSettings.instance;
 
         Properties properties = System.getProperties();
         properties.setProperty("mail.smtps.host", config.getMailSmtpHost());

Mage.Server/src/main/java/mage/server/MailgunClient.java

@@ -19,8 +19,8 @@ public final class MailgunClient {
             return false;
         }
         Client client = Client.create();
-        client.addFilter(new HTTPBasicAuthFilter("api", ConfigSettings.getInstance().getMailgunApiKey()));
+        client.addFilter(new HTTPBasicAuthFilter("api", ConfigSettings.instance.getMailgunApiKey()));
-        String domain = ConfigSettings.getInstance().getMailgunDomain();
+        String domain = ConfigSettings.instance.getMailgunDomain();
         WebResource webResource = client.resource("https://api.mailgun.net/v3/" + domain + "/messages");
         MultivaluedMapImpl formData = new MultivaluedMapImpl();
         formData.add("from", "XMage <postmaster@" + domain + '>');

Mage.Server/src/main/java/mage/server/Main.java

@@ -107,7 +107,7 @@ public final class Main {
             }
         }
 
-        if (ConfigSettings.getInstance().isAuthenticationActivated()) {
+        if (ConfigSettings.instance.isAuthenticationActivated()) {
             logger.info("Check authorized user DB version ...");
             if (!AuthorizedUserRepository.instance.checkAlterAndMigrateAuthorizedUser()) {
                 logger.fatal("Failed to start server.");
@@ -162,7 +162,7 @@ public final class Main {
         UserStatsRepository.instance.updateUserStats();
         logger.info("Done.");
         deleteSavedGames();
-        ConfigSettings config = ConfigSettings.getInstance();
+        ConfigSettings config = ConfigSettings.instance;
         for (GamePlugin plugin : config.getGameTypes()) {
             GameFactory.getInstance().addGameType(plugin.getName(), loadGameType(plugin), loadPlugin(plugin));
         }
@@ -240,7 +240,7 @@ public final class Main {
     }
 
     static void initStatistics() {
-        ServerMessagesUtil.getInstance().setStartDate(System.currentTimeMillis());
+        ServerMessagesUtil.instance.setStartDate(System.currentTimeMillis());
     }
 
     static boolean isAlreadyRunning(InvokerLocator serverLocator) {
@@ -263,11 +263,11 @@ public final class Main {
 
         @Override
         public void handleConnectionException(Throwable throwable, Client client) {
-            Session session = SessionManager.getInstance().getSession(client.getSessionId());
+            Session session = SessionManager.instance.getSession(client.getSessionId());
             if (session != null) {
 
                 StringBuilder sessionInfo = new StringBuilder();
-                Optional<User> user = UserManager.getInstance().getUser(session.getUserId());
+                Optional<User> user = UserManager.instance.getUser(session.getUserId());
                 if (user.isPresent()) {
                     sessionInfo.append(user.get().getName()).append(" [").append(user.get().getGameInfo()).append(']');
                 } else {
@@ -277,12 +277,12 @@ public final class Main {
                 if (throwable instanceof ClientDisconnectedException) {
                     // Seems like the random diconnects from public server land here and should not be handled as explicit disconnects
                     // So it should be possible to reconnect to server and continue games if DisconnectReason is set to LostConnection
-                    //SessionManager.getInstance().disconnect(client.getSessionId(), DisconnectReason.Disconnected);
+                    //SessionManager.instance.disconnect(client.getSessionId(), DisconnectReason.Disconnected);
-                    SessionManager.getInstance().disconnect(client.getSessionId(), DisconnectReason.LostConnection);
+                    SessionManager.instance.disconnect(client.getSessionId(), DisconnectReason.LostConnection);
                     logger.info("CLIENT DISCONNECTED - " + sessionInfo);
                     logger.debug("Stack Trace", throwable);
                 } else {
-                    SessionManager.getInstance().disconnect(client.getSessionId(), DisconnectReason.LostConnection);
+                    SessionManager.instance.disconnect(client.getSessionId(), DisconnectReason.LostConnection);
                     logger.info("LOST CONNECTION - " + sessionInfo);
                     if (logger.isDebugEnabled()) {
                         if (throwable == null) {
@@ -305,7 +305,7 @@ public final class Main {
         public MageTransporterServer(InvokerLocator locator, Object target, String subsystem, MageServerInvocationHandler serverInvocationHandler) throws Exception {
             super(locator, target, subsystem);
             connector.addInvocationHandler("callback", serverInvocationHandler);
-            connector.setLeasePeriod(ConfigSettings.getInstance().getLeasePeriod());
+            connector.setLeasePeriod(ConfigSettings.instance.getLeasePeriod());
             connector.addConnectionListener(new ClientConnectionListener());
         }
 
@@ -343,9 +343,9 @@ public final class Main {
 
         @Override
         public void setInvoker(ServerInvoker invoker) {
-            ((BisocketServerInvoker) invoker).setSecondaryBindPort(ConfigSettings.getInstance().getSecondaryBindPort());
+            ((BisocketServerInvoker) invoker).setSecondaryBindPort(ConfigSettings.instance.getSecondaryBindPort());
-            ((BisocketServerInvoker) invoker).setBacklog(ConfigSettings.getInstance().getBacklogSize());
+            ((BisocketServerInvoker) invoker).setBacklog(ConfigSettings.instance.getBacklogSize());
-            ((BisocketServerInvoker) invoker).setNumAcceptThreads(ConfigSettings.getInstance().getNumAcceptThreads());
+            ((BisocketServerInvoker) invoker).setNumAcceptThreads(ConfigSettings.instance.getNumAcceptThreads());
         }
 
         @Override
@@ -354,7 +354,7 @@ public final class Main {
             ServerInvokerCallbackHandler handler = (ServerInvokerCallbackHandler) callbackHandler;
             try {
                 String sessionId = handler.getClientSessionId();
-                SessionManager.getInstance().createSession(sessionId, callbackHandler);
+                SessionManager.instance.createSession(sessionId, callbackHandler);
             } catch (Throwable ex) {
                 logger.fatal("", ex);
             }
@@ -372,7 +372,7 @@ public final class Main {
             } else {
                 host = "localhost";
             }
-            SessionManager.getInstance().getSession(sessionId).setHost(host);
+            SessionManager.instance.getSession(sessionId).setHost(host);
             return null;
         }
 
@@ -380,7 +380,7 @@ public final class Main {
         public void removeListener(InvokerCallbackHandler callbackHandler) {
             ServerInvokerCallbackHandler handler = (ServerInvokerCallbackHandler) callbackHandler;
             String sessionId = handler.getClientSessionId();
-            SessionManager.getInstance().disconnect(sessionId, DisconnectReason.Disconnected);
+            SessionManager.instance.disconnect(sessionId, DisconnectReason.Disconnected);
         }
 
     }

Mage.Server/src/main/java/mage/server/RoomImpl.java

@@ -41,7 +41,7 @@ public abstract class RoomImpl implements Room {
 
     public RoomImpl() {
         roomId = UUID.randomUUID();
-        chatId = ChatManager.getInstance().createChatSession("Room " + roomId);
+        chatId = ChatManager.instance.createChatSession("Room " + roomId);
     }
 
     /**

Mage.Server/src/main/java/mage/server/Session.java

@@ -76,7 +76,7 @@ public class Session {
     }
 
     public String registerUser(String userName, String password, String email) throws MageException {
-        if (!ConfigSettings.getInstance().isAuthenticationActivated()) {
+        if (!ConfigSettings.instance.isAuthenticationActivated()) {
             String returnMessage = "Registration is disabled by the server config";
             sendErrorMessageToClient(returnMessage);
             return returnMessage;
@@ -106,7 +106,7 @@ public class Session {
 
             boolean success;
             String subject = "XMage Registration Completed";
-            if (!ConfigSettings.getInstance().getMailUser().isEmpty()) {
+            if (!ConfigSettings.instance.getMailUser().isEmpty()) {
                 success = MailClient.sendMessage(email, subject, text);
             } else {
                 success = MailgunClient.sendMessage(email, subject, text);
@@ -133,14 +133,14 @@ public class Session {
         if (userName.equals("Admin")) {
             return "User name Admin already in use";
         }
-        ConfigSettings config = ConfigSettings.getInstance();
+        ConfigSettings config = ConfigSettings.instance;
         if (userName.length() < config.getMinUserNameLength()) {
             return "User name may not be shorter than " + config.getMinUserNameLength() + " characters";
         }
         if (userName.length() > config.getMaxUserNameLength()) {
             return "User name may not be longer than " + config.getMaxUserNameLength() + " characters";
         }
-        Pattern invalidUserNamePattern = Pattern.compile(ConfigSettings.getInstance().getInvalidUserNamePattern(), Pattern.CASE_INSENSITIVE);
+        Pattern invalidUserNamePattern = Pattern.compile(ConfigSettings.instance.getInvalidUserNamePattern(), Pattern.CASE_INSENSITIVE);
         Matcher m = invalidUserNamePattern.matcher(userName);
         if (m.find()) {
             return "User name '" + userName + "' includes not allowed characters: use a-z, A-Z and 0-9";
@@ -153,7 +153,7 @@ public class Session {
     }
 
     static private String validatePassword(String password, String userName) {
-        ConfigSettings config = ConfigSettings.getInstance();
+        ConfigSettings config = ConfigSettings.instance;
         if (password.length() < config.getMinPasswordLength()) {
             return "Password may not be shorter than " + config.getMinPasswordLength() + " characters";
         }
@@ -198,7 +198,7 @@ public class Session {
     public String connectUserHandling(String userName, String password) throws MageException {
         this.isAdmin = false;
         AuthorizedUser authorizedUser = null;
-        if (ConfigSettings.getInstance().isAuthenticationActivated()) {
+        if (ConfigSettings.instance.isAuthenticationActivated()) {
             authorizedUser = AuthorizedUserRepository.instance.getByName(userName);
             String errorMsg = "Wrong username or password. In case you haven't, please register your account first.";
             if (authorizedUser == null) {
@@ -216,19 +216,19 @@ public class Session {
                 if (authorizedUser.lockedUntil.compareTo(Calendar.getInstance().getTime()) > 0) {
                     return "Your profile is deactivated until " + SystemUtil.dateFormat.format(authorizedUser.lockedUntil);
                 } else {
-                    User user = UserManager.getInstance().createUser(userName, host, authorizedUser);
+                    User user = UserManager.instance.createUser(userName, host, authorizedUser);
                     if (user != null && authorizedUser.lockedUntil != null) {
                         user.setLockedUntil(null);
                     }
                 }
             }
         }
-        User user = UserManager.getInstance().createUser(userName, host, authorizedUser);
+        User user = UserManager.instance.createUser(userName, host, authorizedUser);
         boolean reconnect = false;
         if (user == null) {  // user already exists
-            user = UserManager.getInstance().getUserByName(userName);
+            user = UserManager.instance.getUserByName(userName);
             // If authentication is not activated, check the identity using IP address.
-            if (ConfigSettings.getInstance().isAuthenticationActivated() || user.getHost().equals(host)) {
+            if (ConfigSettings.instance.isAuthenticationActivated() || user.getHost().equals(host)) {
                 user.updateLastActivity(null);  // minimizes possible expiration
                 this.userId = user.getId();
                 if (user.getSessionId().isEmpty()) {
@@ -237,43 +237,43 @@ public class Session {
                 } else {
                     //disconnect previous session
                     logger.info("Disconnecting another user instance: " + userName);
-                    SessionManager.getInstance().disconnect(user.getSessionId(), DisconnectReason.ConnectingOtherInstance);
+                    SessionManager.instance.disconnect(user.getSessionId(), DisconnectReason.ConnectingOtherInstance);
                 }
             } else {
                 return "User name " + userName + " already in use (or your IP address changed)";
             }
         }
-        if (!UserManager.getInstance().connectToSession(sessionId, user.getId())) {
+        if (!UserManager.instance.connectToSession(sessionId, user.getId())) {
             return "Error connecting " + userName;
         }
         this.userId = user.getId();
         if (reconnect) { // must be connected to receive the message
-            UUID chatId = GamesRoomManager.getInstance().getRoom(GamesRoomManager.getInstance().getMainRoomId()).getChatId();
+            UUID chatId = GamesRoomManager.instance.getRoom(GamesRoomManager.instance.getMainRoomId()).getChatId();
             if (chatId != null) {
-                ChatManager.getInstance().joinChat(chatId, userId);
+                ChatManager.instance.joinChat(chatId, userId);
             }
-            ChatManager.getInstance().sendReconnectMessage(userId);
+            ChatManager.instance.sendReconnectMessage(userId);
         }
         return null;
     }
 
     public void connectAdmin() {
         this.isAdmin = true;
-        User user = UserManager.getInstance().createUser("Admin", host, null);
+        User user = UserManager.instance.createUser("Admin", host, null);
         if (user == null) {
-            user = UserManager.getInstance().getUserByName("Admin");
+            user = UserManager.instance.getUserByName("Admin");
         }
         UserData adminUserData = UserData.getDefaultUserDataView();
         adminUserData.setGroupId(UserGroup.ADMIN.getGroupId());
         user.setUserData(adminUserData);
-        if (!UserManager.getInstance().connectToSession(sessionId, user.getId())) {
+        if (!UserManager.instance.connectToSession(sessionId, user.getId())) {
             logger.info("Error connecting Admin!");
         }
         this.userId = user.getId();
     }
 
     public boolean setUserData(String userName, UserData userData, String clientVersion, String userIdStr) {
-        User user = UserManager.getInstance().getUserByName(userName);
+        User user = UserManager.instance.getUserByName(userName);
         if (user != null) {
             if (clientVersion != null) {
                 user.setClientVersion(clientVersion);
@@ -326,7 +326,7 @@ public class Session {
             } else {
                 logger.error("CAN'T GET LOCK - userId: " + userId + " hold count: " + lock.getHoldCount());
             }
-            Optional<User> _user = UserManager.getInstance().getUser(userId);
+            Optional<User> _user = UserManager.instance.getUser(userId);
             if (!_user.isPresent()) {
                 return; //user was already disconnected by other thread
             }
@@ -340,7 +340,7 @@ public class Session {
                 return;
             }
             // logger.info("LOST CONNECTION - " + user.getName() + " id: " + userId);
-            UserManager.getInstance().disconnect(userId, DisconnectReason.LostConnection);
+            UserManager.instance.disconnect(userId, DisconnectReason.LostConnection);
 
         } catch (InterruptedException ex) {
             logger.error("SESSION LOCK lost connection - userId: " + userId, ex);
@@ -362,7 +362,7 @@ public class Session {
             } else {
                 logger.error("SESSION LOCK - kill: userId " + userId);
             }
-            UserManager.getInstance().removeUser(userId, reason);
+            UserManager.instance.removeUser(userId, reason);
         } catch (InterruptedException ex) {
             logger.error("SESSION LOCK - kill: userId " + userId, ex);
         } finally {
@@ -381,7 +381,7 @@ public class Session {
             callbackHandler.handleCallbackOneway(new Callback(call));
         } catch (HandleCallbackException ex) {
             ex.printStackTrace();
-            UserManager.getInstance().getUser(userId).ifPresent(user-> {
+            UserManager.instance.getUser(userId).ifPresent(user-> {
                 logger.warn("SESSION CALLBACK EXCEPTION - " + user.getName() + " userId " + userId);
                 logger.warn(" - method: " + call.getMethod());
                 logger.warn(" - cause: " + getBasicCause(ex).toString());

Mage.Server/src/main/java/mage/server/SessionManager.java

@@ -42,20 +42,16 @@ import javax.annotation.Nonnull;
 /**
  * @author BetaSteward_at_googlemail.com
  */
-public class SessionManager {
+public enum SessionManager {
-
+    instance;
     private static final Logger logger = Logger.getLogger(SessionManager.class);
-    private static final SessionManager INSTANCE = new SessionManager();
 
-    public static SessionManager getInstance() {
-        return INSTANCE;
-    }
 
     private final ConcurrentHashMap<String, Session> sessions = new ConcurrentHashMap<>();
 
     public Session getSession(@Nonnull String sessionId) {
         Session session = sessions.get(sessionId);
-        if (session != null && session.getUserId() != null && UserManager.getInstance().getUser(session.getUserId()) == null) {
+        if (session != null && session.getUserId() != null && UserManager.instance.getUser(session.getUserId()) == null) {
             logger.error("User for session " + sessionId + " with userId " + session.getUserId() + " is missing. Session removed.");
             // can happen if user from same host signs in multiple time with multiple clients, after he disconnects with one client
             disconnect(sessionId, DisconnectReason.ConnectingOtherInstance);
@@ -191,7 +187,7 @@ public class SessionManager {
         if (session == null) {
             return null;
         }
-        return UserManager.getInstance().getUser(session.getUserId()).get();
+        return UserManager.instance.getUser(session.getUserId()).get();
     }
 
     public void endUserSession(String sessionId, String userSessionId) {
@@ -215,7 +211,7 @@ public class SessionManager {
     public Optional<User> getUser(@Nonnull String sessionId) {
         Session session = sessions.get(sessionId);
         if (session != null) {
-            return UserManager.getInstance().getUser(sessions.get(sessionId).getUserId());
+            return UserManager.instance.getUser(sessions.get(sessionId).getUserId());
         }
         logger.error(String.format("Session %s could not be found", sessionId));
         return Optional.empty();
@@ -224,7 +220,7 @@ public class SessionManager {
     public boolean extendUserSession(String sessionId, String pingInfo) {
         Session session = sessions.get(sessionId);
         if (session != null) {
-            return UserManager.getInstance().extendUserSession(session.getUserId(), pingInfo);
+            return UserManager.instance.extendUserSession(session.getUserId(), pingInfo);
         }
         return false;
     }

Mage.Server/src/main/java/mage/server/TableController.java

@@ -94,14 +94,14 @@ public class TableController {
         this.options = options;
         match = GameFactory.getInstance().createMatch(options.getGameType(), options);
         if (userId != null) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             // TODO: Handle if user == null
             controllerName = user.map(User::getName).orElse("undefined");
         } else {
             controllerName = "System";
         }
         table = new Table(roomId, options.getGameType(), options.getName(), controllerName, DeckValidatorFactory.getInstance().createDeckValidator(options.getDeckType()), options.getPlayerTypes(), TableRecorderImpl.getInstance(), match, options.getBannedUsers());
-        chatId = ChatManager.getInstance().createChatSession("Match Table " + table.getId());
+        chatId = ChatManager.instance.createChatSession("Match Table " + table.getId());
         init();
     }
 
@@ -109,7 +109,7 @@ public class TableController {
         this.userId = userId;
         tournament = TournamentFactory.getInstance().createTournament(options.getTournamentType(), options);
         if (userId != null) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             if (!user.isPresent()) {
                 logger.fatal(new StringBuilder("User for userId ").append(userId).append(" could not be retrieved from UserManager").toString());
                 controllerName = "[unknown]";
@@ -120,7 +120,7 @@ public class TableController {
             controllerName = "System";
         }
         table = new Table(roomId, options.getTournamentType(), options.getName(), controllerName, DeckValidatorFactory.getInstance().createDeckValidator(options.getMatchOptions().getDeckType()), options.getPlayerTypes(), TableRecorderImpl.getInstance(), tournament, options.getMatchOptions().getBannedUsers());
-        chatId = ChatManager.getInstance().createChatSession("Tourn. table " + table.getId());
+        chatId = ChatManager.instance.createChatSession("Tourn. table " + table.getId());
     }
 
     private void init() {
@@ -148,7 +148,7 @@ public class TableController {
         if (seat == null) {
             throw new GameException("No available seats.");
         }
-        Optional<User> _user = UserManager.getInstance().getUser(userId);
+        Optional<User> _user = UserManager.instance.getUser(userId);
         if (!_user.isPresent()) {
             logger.fatal(new StringBuilder("couldn't get user ").append(name).append(" for join tournament userId = ").append(userId).toString());
             return false;
@@ -182,7 +182,7 @@ public class TableController {
                 user.showUserMessage("Join Table", sb.toString());
                 if (isOwner(userId)) {
                     logger.debug("New table removed because owner submitted invalid deck tableId " + table.getId());
-                    TableManager.getInstance().removeTable(table.getId());
+                    TableManager.instance.removeTable(table.getId());
                 }
                 return false;
             }
@@ -242,12 +242,12 @@ public class TableController {
         newTournamentPlayer.setState(oldTournamentPlayer.getState());
         newTournamentPlayer.setReplacedTournamentPlayer(oldTournamentPlayer);
 
-        DraftManager.getInstance().getController(table.getId()).replacePlayer(oldPlayer, newPlayer);
+        DraftManager.instance.getController(table.getId()).replacePlayer(oldPlayer, newPlayer);
         return true;
     }
 
     public synchronized boolean joinTable(UUID userId, String name, String playerType, int skill, DeckCardLists deckList, String password) throws MageException {
-        Optional<User> _user = UserManager.getInstance().getUser(userId);
+        Optional<User> _user = UserManager.instance.getUser(userId);
         if (!_user.isPresent()) {
             return false;
         }
@@ -283,7 +283,7 @@ public class TableController {
             user.showUserMessage("Join Table", sb.toString());
             if (isOwner(userId)) {
                 logger.debug("New table removed because owner submitted invalid deck tableId " + table.getId());
-                TableManager.getInstance().removeTable(table.getId());
+                TableManager.instance.removeTable(table.getId());
             }
             return false;
         }
@@ -433,17 +433,17 @@ public class TableController {
     private void submitDeck(UUID userId, UUID playerId, Deck deck) {
         if (table.getState() == TableState.SIDEBOARDING) {
             match.submitDeck(playerId, deck);
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.removeSideboarding(table.getId()));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.removeSideboarding(table.getId()));
         } else {
-            TournamentManager.getInstance().submitDeck(tournament.getId(), playerId, deck);
+            TournamentManager.instance.submitDeck(tournament.getId(), playerId, deck);
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.removeConstructing(playerId));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.removeConstructing(playerId));
         }
     }
 
     private void updateDeck(UUID userId, UUID playerId, Deck deck) {
         if (table.isTournament()) {
             if (tournament != null) {
-                TournamentManager.getInstance().updateDeck(tournament.getId(), playerId, deck);
+                TournamentManager.instance.updateDeck(tournament.getId(), playerId, deck);
             } else {
                 logger.fatal("Tournament == null  table: " + table.getId() + " userId: " + userId);
             }
@@ -456,7 +456,7 @@ public class TableController {
 
     public boolean watchTable(UUID userId) {
         if (table.isTournament()) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.ccShowTournament(table.getTournament().getId()));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.ccShowTournament(table.getTournament().getId()));
             return true;
         } else {
             if (table.isTournamentSubTable() && !table.getTournament().getOptions().isWatchingAllowed()) {
@@ -469,7 +469,7 @@ public class TableController {
             if (userPlayerMap.get(userId) != null) {
                 return false;
             }
-            return UserManager.getInstance().getUser(userId).get().ccWatchGame(match.getGame().getId());
+            return UserManager.instance.getUser(userId).get().ccWatchGame(match.getGame().getId());
         }
     }
 
@@ -477,7 +477,7 @@ public class TableController {
 //        if (table.getState() != TableState.FINISHED) {
 //            return false;
 //        }
-//        ReplayManager.getInstance().replayGame(table.getId(), userId);
+//        ReplayManager.instance.replayGame(table.getId(), userId);
 //        return true;
 //    }
     private Optional<Player> createPlayer(String name, String playerType, int skill) {
@@ -514,7 +514,7 @@ public class TableController {
                 && (table.getState() == TableState.WAITING
                 || table.getState() == TableState.READY_TO_START)) {
             // table not started yet and user is the owner, remove the table
-            TableManager.getInstance().removeTable(table.getId());
+            TableManager.instance.removeTable(table.getId());
         } else {
             UUID playerId = userPlayerMap.get(userId);
             if (playerId != null) {
@@ -525,9 +525,9 @@ public class TableController {
                     } else {
                         match.quitMatch(playerId);
                     }
-                    Optional<User> user = UserManager.getInstance().getUser(userId);
+                    Optional<User> user = UserManager.instance.getUser(userId);
                     if (!user.isPresent()) {
-                        ChatManager.getInstance().broadcast(chatId, user.get().getName(), "has left the table", ChatMessage.MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, ChatMessage.SoundToPlay.PlayerLeft);
+                        ChatManager.instance.broadcast(chatId, user.get().getName(), "has left the table", ChatMessage.MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, ChatMessage.SoundToPlay.PlayerLeft);
                         if (!table.isTournamentSubTable()) {
                             user.get().removeTable(playerId);
                         }
@@ -538,9 +538,9 @@ public class TableController {
                 } else if (table.getState() != TableState.FINISHED) {
                     if (table.isTournament()) {
                         logger.debug("Quit tournament sub tables for userId: " + userId);
-                        TableManager.getInstance().userQuitTournamentSubTables(tournament.getId(), userId);
+                        TableManager.instance.userQuitTournamentSubTables(tournament.getId(), userId);
                         logger.debug("Quit tournament  Id: " + table.getTournament().getId() + '(' + table.getTournament().getTournamentState() + ')');
-                        TournamentManager.getInstance().quit(tournament.getId(), userId);
+                        TournamentManager.instance.quit(tournament.getId(), userId);
                     } else {
                         MatchPlayer matchPlayer = match.getPlayer(playerId);
                         if (matchPlayer != null && !match.hasEnded() && !matchPlayer.hasQuit()) {
@@ -548,7 +548,7 @@ public class TableController {
                             if (game != null && !game.hasEnded()) {
                                 Player player = match.getPlayer(playerId).getPlayer();
                                 if (player != null && player.isInGame()) {
-                                    GameManager.getInstance().quitMatch(game.getId(), userId);
+                                    GameManager.instance.quitMatch(game.getId(), userId);
                                 }
                                 match.quitMatch(playerId);
                             } else {
@@ -586,7 +586,7 @@ public class TableController {
                 if (table.isTournamentSubTable()) {
                     logger.info("Tourn. match started id:" + match.getId() + " tournId: " + table.getTournament().getId());
                 } else {
-                    UserManager.getInstance().getUser(userId).ifPresent(user -> {
+                    UserManager.instance.getUser(userId).ifPresent(user -> {
                         logger.info("MATCH started [" + match.getName() + "] " + match.getId() + '(' + user.getName() + ')');
                         logger.debug("- " + match.getOptions().getGameType() + " - " + match.getOptions().getDeckType());
                     });
@@ -607,12 +607,12 @@ public class TableController {
             GameOptions gameOptions = new GameOptions();
             gameOptions.rollbackTurnsAllowed = match.getOptions().isRollbackTurnsAllowed();
             match.getGame().setGameOptions(gameOptions);
-            GameManager.getInstance().createGameSession(match.getGame(), userPlayerMap, table.getId(), choosingPlayerId, gameOptions);
+            GameManager.instance.createGameSession(match.getGame(), userPlayerMap, table.getId(), choosingPlayerId, gameOptions);
             String creator = null;
             StringBuilder opponent = new StringBuilder();
             for (Entry<UUID, UUID> entry : userPlayerMap.entrySet()) { // do only for no AI players
                 if (match.getPlayer(entry.getValue()) != null && !match.getPlayer(entry.getValue()).hasQuit()) {
-                    Optional<User> _user = UserManager.getInstance().getUser(entry.getKey());
+                    Optional<User> _user = UserManager.instance.getUser(entry.getKey());
                     if (_user.isPresent()) {
                         User user = _user.get();
                         user.ccGameStarted(match.getGame().getId(), entry.getValue());
@@ -643,23 +643,23 @@ public class TableController {
                     opponent.append(mPlayer.getName());
                 }
             }
-            ServerMessagesUtil.getInstance().incGamesStarted();
+            ServerMessagesUtil.instance.incGamesStarted();
 
             // log about game started
             logger.info("GAME started " + (match.getGame() != null ? match.getGame().getId() : "no Game") + " [" + match.getName() + "] " + creator + " - " + opponent.toString());
             logger.debug("- matchId: " + match.getId() + " [" + match.getName() + ']');
             if (match.getGame() != null) {
-                logger.debug("- chatId:  " + GameManager.getInstance().getChatId(match.getGame().getId()));
+                logger.debug("- chatId:  " + GameManager.instance.getChatId(match.getGame().getId()));
             }
         } catch (Exception ex) {
             logger.fatal("Error starting game table: " + table.getId(), ex);
             if (table != null) {
-                TableManager.getInstance().removeTable(table.getId());
+                TableManager.instance.removeTable(table.getId());
             }
             if (match != null) {
                 Game game = match.getGame();
                 if (game != null) {
-                    GameManager.getInstance().removeGame(game.getId());
+                    GameManager.instance.removeGame(game.getId());
                 }
             }
         }
@@ -669,27 +669,27 @@ public class TableController {
         try {
             if (userId.equals(this.userId) && table.getState() == TableState.STARTING) {
                 tournament.setStartTime();
-                TournamentManager.getInstance().createTournamentSession(tournament, userPlayerMap, table.getId());
+                TournamentManager.instance.createTournamentSession(tournament, userPlayerMap, table.getId());
                 for (Entry<UUID, UUID> entry : userPlayerMap.entrySet()) {
-                    UserManager.getInstance().getUser(entry.getKey()).ifPresent(user -> {
+                    UserManager.instance.getUser(entry.getKey()).ifPresent(user -> {
                         logger.info(new StringBuilder("User ").append(user.getName()).append(" tournament started: ").append(tournament.getId()).append(" userId: ").append(user.getId()));
                         user.ccTournamentStarted(tournament.getId(), entry.getValue());
                     });
                 }
-                ServerMessagesUtil.getInstance().incTournamentsStarted();
+                ServerMessagesUtil.instance.incTournamentsStarted();
             }
         } catch (Exception ex) {
             logger.fatal("Error starting tournament", ex);
-            TableManager.getInstance().removeTable(table.getId());
+            TableManager.instance.removeTable(table.getId());
-            TournamentManager.getInstance().quit(tournament.getId(), userId);
+            TournamentManager.instance.quit(tournament.getId(), userId);
         }
     }
 
     public void startDraft(Draft draft) {
         table.initDraft();
-        DraftManager.getInstance().createDraftSession(draft, userPlayerMap, table.getId());
+        DraftManager.instance.createDraftSession(draft, userPlayerMap, table.getId());
         for (Entry<UUID, UUID> entry : userPlayerMap.entrySet()) {
-            Optional<User> user = UserManager.getInstance().getUser(entry.getKey());
+            Optional<User> user = UserManager.instance.getUser(entry.getKey());
             if (user.isPresent()) {
                 logger.info(new StringBuilder("User ").append(user.get().getName()).append(" draft started: ").append(draft.getId()).append(" userId: ").append(user.get().getId()));
                 user.get().ccDraftStarted(draft.getId(), entry.getValue());
@@ -703,7 +703,7 @@ public class TableController {
 
         for (Entry<UUID, UUID> entry : userPlayerMap.entrySet()) {
             if (entry.getValue().equals(playerId)) {
-                Optional<User> user = UserManager.getInstance().getUser(entry.getKey());
+                Optional<User> user = UserManager.instance.getUser(entry.getKey());
                 int remaining = (int) futureTimeout.getDelay(TimeUnit.SECONDS);
                 user.ifPresent(user1 -> user1.ccSideboard(deck, table.getId(), remaining, options.isLimited()));
                 break;
@@ -744,12 +744,12 @@ public class TableController {
         }
         UUID choosingPlayerId = match.getChooser();
         match.endGame();
-        if (ConfigSettings.getInstance().isSaveGameActivated() && !game.isSimulation()) {
+        if (ConfigSettings.instance.isSaveGameActivated() && !game.isSimulation()) {
-            if (GameManager.getInstance().saveGame(game.getId())) {
+            if (GameManager.instance.saveGame(game.getId())) {
                 match.setReplayAvailable(true);
             }
         }
-        GameManager.getInstance().removeGame(game.getId());
+        GameManager.instance.removeGame(game.getId());
         try {
             if (!match.hasEnded()) {
                 if (match.getGame() != null && match.getGame().getGameType().isSideboardingAllowed()) {
@@ -810,7 +810,7 @@ public class TableController {
                 // opponent(s) left during sideboarding
                 if (matchPlayer != null) {
                     if (!matchPlayer.hasQuit()) {
-                        UserManager.getInstance().getUser(entry.getKey()).ifPresent(user -> {
+                        UserManager.instance.getUser(entry.getKey()).ifPresent(user -> {
                             if (table.getState() == TableState.SIDEBOARDING) {
                                 StringBuilder sb = new StringBuilder();
                                 if (table.isTournamentSubTable()) {
@@ -835,7 +835,7 @@ public class TableController {
                     }
                 }
                 // free resources no longer needed
-                match.cleanUpOnMatchEnd(ConfigSettings.getInstance().isSaveGameActivated(), table.isTournament());
+                match.cleanUpOnMatchEnd(ConfigSettings.instance.isSaveGameActivated(), table.isTournament());
             }
         }
     }
@@ -907,7 +907,7 @@ public class TableController {
     public boolean isTournamentStillValid() {
         if (table.getTournament() != null) {
             if (table.getState() != TableState.WAITING && table.getState() != TableState.READY_TO_START && table.getState() != TableState.STARTING) {
-                TournamentController tournamentController = TournamentManager.getInstance().getTournamentController(table.getTournament().getId());
+                TournamentController tournamentController = TournamentManager.instance.getTournamentController(table.getTournament().getId());
                 if (tournamentController != null) {
                     return tournamentController.isTournamentStillValid(table.getState());
                 } else {
@@ -915,7 +915,7 @@ public class TableController {
                 }
             } else {
                 // check if table creator is still a valid user, if not remove table
-                return UserManager.getInstance().getUser(userId).isPresent();
+                return UserManager.instance.getUser(userId).isPresent();
             }
         }
         return false;
@@ -981,7 +981,7 @@ public class TableController {
                             || table.getState() == TableState.READY_TO_START)
                             || !match.isDoneSideboarding()
                             || (!matchPlayer.hasQuit() && match.getGame() != null && matchPlayer.getPlayer().isInGame())) {
-                        Optional<User> user = UserManager.getInstance().getUser(userPlayerEntry.getKey());
+                        Optional<User> user = UserManager.instance.getUser(userPlayerEntry.getKey());
                         if (!user.isPresent()) {
                             logger.debug("- Active user of match is missing: " + matchPlayer.getName());
                             logger.debug("-- matchId:" + match.getId());
@@ -1005,12 +1005,12 @@ public class TableController {
     void cleanUp() {
         if (!table.isTournamentSubTable()) {
             for (Map.Entry<UUID, UUID> entry : userPlayerMap.entrySet()) {
-                UserManager.getInstance().getUser(entry.getKey()).ifPresent(user
+                UserManager.instance.getUser(entry.getKey()).ifPresent(user
                         -> user.removeTable(entry.getValue()));
             }
 
         }
-        ChatManager.getInstance().destroyChatSession(chatId);
+        ChatManager.instance.destroyChatSession(chatId);
     }
 
     public synchronized TableState getTableState() {

Mage.Server/src/main/java/mage/server/TableManager.java

@@ -59,14 +59,13 @@ import org.apache.log4j.Logger;
 /**
  * @author BetaSteward_at_googlemail.com
  */
-public class TableManager {
+public enum TableManager {
-
+    instance;
-    protected static final ScheduledExecutorService expireExecutor = Executors.newSingleThreadScheduledExecutor();
+    protected final ScheduledExecutorService expireExecutor = Executors.newSingleThreadScheduledExecutor();
 
     // protected static ScheduledExecutorService expireExecutor = ThreadExecutor.getInstance().getExpireExecutor();
 
-    private static final TableManager INSTANCE = new TableManager();
+    private final Logger logger = Logger.getLogger(TableManager.class);
-    private static final Logger logger = Logger.getLogger(TableManager.class);
     private static final DateFormat formatter = new SimpleDateFormat("HH:mm:ss");
 
     private final ConcurrentHashMap<UUID, TableController> controllers = new ConcurrentHashMap<>();
@@ -79,11 +78,8 @@ public class TableManager {
      */
     private static final int EXPIRE_CHECK_PERIOD = 10;
 
-    public static TableManager getInstance() {
-        return INSTANCE;
-    }
 
-    private TableManager() {
+    TableManager() {
         expireExecutor.scheduleAtFixedRate(() -> {
             try {
                 checkTableHealthState();
@@ -151,7 +147,7 @@ public class TableManager {
         if (controllers.containsKey(tableId)) {
             return controllers.get(tableId).submitDeck(userId, deckList);
         }
-        UserManager.getInstance().getUser(userId).ifPresent(user -> {
+        UserManager.instance.getUser(userId).ifPresent(user -> {
             user.removeSideboarding(tableId);
             user.showUserMessage("Submit deck", "Table no longer active");
 
@@ -198,12 +194,12 @@ public class TableManager {
     }
 
     public boolean removeTable(UUID userId, UUID tableId) {
-        if (isTableOwner(tableId, userId) || UserManager.getInstance().isAdmin(userId)) {
+        if (isTableOwner(tableId, userId) || UserManager.instance.isAdmin(userId)) {
             logger.debug("Table remove request - userId: " + userId + " tableId: " + tableId);
             TableController tableController = controllers.get(tableId);
             if (tableController != null) {
                 tableController.leaveTableAll();
-                ChatManager.getInstance().destroyChatSession(tableController.getChatId());
+                ChatManager.instance.destroyChatSession(tableController.getChatId());
                 removeTable(tableId);
             }
             return true;
@@ -236,7 +232,7 @@ public class TableManager {
         if (controllers.containsKey(tableId)) {
             controllers.get(tableId).startMatch(userId);
             // chat of start dialog can be killed
-            ChatManager.getInstance().destroyChatSession(controllers.get(tableId).getChatId());
+            ChatManager.instance.destroyChatSession(controllers.get(tableId).getChatId());
         }
     }
 
@@ -255,7 +251,7 @@ public class TableManager {
     public void startTournament(UUID userId, UUID roomId, UUID tableId) {
         if (controllers.containsKey(tableId)) {
             controllers.get(tableId).startTournament(userId);
-            ChatManager.getInstance().destroyChatSession(controllers.get(tableId).getChatId());
+            ChatManager.instance.destroyChatSession(controllers.get(tableId).getChatId());
         }
     }
 
@@ -343,9 +339,9 @@ public class TableManager {
             // If table is not finished, the table has to be removed completly because it's not a normal state (if finished it will be removed in GamesRoomImpl.Update())
             if (table.getState() != TableState.FINISHED) {
                 if (game != null) {
-                    GameManager.getInstance().removeGame(game.getId());
+                    GameManager.instance.removeGame(game.getId());
                 }
-                GamesRoomManager.getInstance().removeTable(tableId);
+                GamesRoomManager.instance.removeTable(tableId);
             }
 
         }
@@ -353,10 +349,10 @@ public class TableManager {
 
     public void debugServerState() {
         logger.debug("--- Server state ----------------------------------------------");
-        Collection<User> users = UserManager.getInstance().getUsers();
+        Collection<User> users = UserManager.instance.getUsers();
         logger.debug("--------User: " + users.size() + " [userId | since | lock | name -----------------------");
         for (User user : users) {
-            Session session = SessionManager.getInstance().getSession(user.getSessionId());
+            Session session = SessionManager.instance.getSession(user.getSessionId());
             String sessionState = "N";
             if (session != null) {
                 if (session.isLocked()) {
@@ -370,14 +366,14 @@ public class TableManager {
                     + " | " + sessionState
                     + " | " + user.getName() + " (" + user.getUserState().toString() + " - " + user.getPingInfo() + ')');
         }
-        ArrayList<ChatSession> chatSessions = ChatManager.getInstance().getChatSessions();
+        ArrayList<ChatSession> chatSessions = ChatManager.instance.getChatSessions();
         logger.debug("------- ChatSessions: " + chatSessions.size() + " ----------------------------------");
         for (ChatSession chatSession : chatSessions) {
             logger.debug(chatSession.getChatId() + " " + formatter.format(chatSession.getCreateTime()) + ' ' + chatSession.getInfo() + ' ' + chatSession.getClients().values().toString());
         }
-        logger.debug("------- Games: " + GameManager.getInstance().getNumberActiveGames() + " --------------------------------------------");
+        logger.debug("------- Games: " + GameManager.instance.getNumberActiveGames() + " --------------------------------------------");
         logger.debug(" Active Game Worker: " + ThreadExecutor.getInstance().getActiveThreads(ThreadExecutor.getInstance().getGameExecutor()));
-        for (Entry<UUID, GameController> entry : GameManager.getInstance().getGameController().entrySet()) {
+        for (Entry<UUID, GameController> entry : GameManager.instance.getGameController().entrySet()) {
             logger.debug(entry.getKey() + entry.getValue().getPlayerNameList());
         }
         logger.debug("--- Server state END ------------------------------------------");

Mage.Server/src/main/java/mage/server/User.java

@@ -210,10 +210,10 @@ public class User {
         // Because watched games don't get restored after reconnection call stop watching
         for (Iterator<UUID> iterator = watchedGames.iterator(); iterator.hasNext();) {
             UUID gameId = iterator.next();
-            GameManager.getInstance().stopWatching(gameId, userId);
+            GameManager.instance.stopWatching(gameId, userId);
             iterator.remove();
         }
-        ServerMessagesUtil.getInstance().incLostConnection();
+        ServerMessagesUtil.instance.incLostConnection();
     }
 
     public boolean isConnected() {
@@ -246,7 +246,7 @@ public class User {
 
     public void fireCallback(final ClientCallback call) {
         if (isConnected()) {
-            Session session = SessionManager.getInstance().getSession(sessionId);
+            Session session = SessionManager.instance.getSession(sessionId);
             if (session != null) {
                 session.fireCallback(call);
             }
@@ -304,27 +304,27 @@ public class User {
 
     public void sendPlayerUUID(final UUID gameId, final UUID data) {
         lastActivity = new Date();
-        GameManager.getInstance().sendPlayerUUID(gameId, userId, data);
+        GameManager.instance.sendPlayerUUID(gameId, userId, data);
     }
 
     public void sendPlayerString(final UUID gameId, final String data) {
         lastActivity = new Date();
-        GameManager.getInstance().sendPlayerString(gameId, userId, data);
+        GameManager.instance.sendPlayerString(gameId, userId, data);
     }
 
     public void sendPlayerManaType(final UUID gameId, final UUID playerId, final ManaType data) {
         lastActivity = new Date();
-        GameManager.getInstance().sendPlayerManaType(gameId, playerId, userId, data);
+        GameManager.instance.sendPlayerManaType(gameId, playerId, userId, data);
     }
 
     public void sendPlayerBoolean(final UUID gameId, final Boolean data) {
         lastActivity = new Date();
-        GameManager.getInstance().sendPlayerBoolean(gameId, userId, data);
+        GameManager.instance.sendPlayerBoolean(gameId, userId, data);
     }
 
     public void sendPlayerInteger(final UUID gameId, final Integer data) {
         lastActivity = new Date();
-        GameManager.getInstance().sendPlayerInteger(gameId, userId, data);
+        GameManager.instance.sendPlayerInteger(gameId, userId, data);
     }
 
     public void updateLastActivity(String pingInfo) {
@@ -355,7 +355,7 @@ public class User {
             ccJoinedTable(entry.getValue().getRoomId(), entry.getValue().getId(), entry.getValue().isTournament());
         }
         for (Entry<UUID, UUID> entry : userTournaments.entrySet()) {
-            TournamentController tournamentController = TournamentManager.getInstance().getTournamentController(entry.getValue());
+            TournamentController tournamentController = TournamentManager.instance.getTournamentController(entry.getValue());
             if (tournamentController != null) {
                 ccTournamentStarted(entry.getValue(), entry.getKey());
                 tournamentController.rejoin(entry.getKey());
@@ -365,7 +365,7 @@ public class User {
         for (Entry<UUID, GameSessionPlayer> entry : gameSessions.entrySet()) {
             ccGameStarted(entry.getValue().getGameId(), entry.getKey());
             entry.getValue().init();
-            GameManager.getInstance().sendPlayerString(entry.getValue().getGameId(), userId, "");
+            GameManager.instance.sendPlayerString(entry.getValue().getGameId(), userId, "");
         }
 
         for (Entry<UUID, DraftSession> entry : draftSessions.entrySet()) {
@@ -378,10 +378,10 @@ public class User {
             entry.getValue().construct(0); // TODO: Check if this is correct
         }
         for (Entry<UUID, Deck> entry : sideboarding.entrySet()) {
-            TableController controller = TableManager.getInstance().getController(entry.getKey());
+            TableController controller = TableManager.instance.getController(entry.getKey());
             ccSideboard(entry.getValue(), entry.getKey(), controller.getRemainingTime(), controller.getOptions().isLimited());
         }
-        ServerMessagesUtil.getInstance().incReconnects();
+        ServerMessagesUtil.instance.incReconnects();
         logger.trace(userName + " ended reconnect");
     }
 
@@ -437,29 +437,29 @@ public class User {
         draftSessions.clear();
         logger.trace("REMOVE " + userName + " Tournament sessions " + userTournaments.size());
         for (UUID tournamentId : userTournaments.values()) {
-            TournamentManager.getInstance().quit(tournamentId, userId);
+            TournamentManager.instance.quit(tournamentId, userId);
         }
         userTournaments.clear();
         logger.trace("REMOVE " + userName + " Tables " + tables.size());
         for (Entry<UUID, Table> entry : tables.entrySet()) {
             logger.debug("-- leave tableId: " + entry.getValue().getId());
-            TableManager.getInstance().leaveTable(userId, entry.getValue().getId());
+            TableManager.instance.leaveTable(userId, entry.getValue().getId());
         }
         tables.clear();
         logger.trace("REMOVE " + userName + " Game sessions: " + gameSessions.size());
         for (GameSessionPlayer gameSessionPlayer : gameSessions.values()) {
             logger.debug("-- kill game session of gameId: " + gameSessionPlayer.getGameId());
-            GameManager.getInstance().quitMatch(gameSessionPlayer.getGameId(), userId);
+            GameManager.instance.quitMatch(gameSessionPlayer.getGameId(), userId);
             gameSessionPlayer.quitGame();
         }
         gameSessions.clear();
         logger.trace("REMOVE " + userName + " watched Games " + watchedGames.size());
         for (UUID gameId : watchedGames) {
-            GameManager.getInstance().stopWatching(gameId, userId);
+            GameManager.instance.stopWatching(gameId, userId);
         }
         watchedGames.clear();
         logger.trace("REMOVE " + userName + " Chats ");
-        ChatManager.getInstance().removeUser(userId, reason);
+        ChatManager.instance.removeUser(userId, reason);
     }
 
     public void setUserData(UserData userData) {
@@ -784,7 +784,7 @@ public class User {
             if (table.getState() == TableState.FINISHED) {
                 number++;
             } else {
-                TableController tableController = TableManager.getInstance().getController(table.getId());
+                TableController tableController = TableManager.instance.getController(table.getId());
                 if (tableController != null && tableController.isUserStillActive(userId)) {
                     number++;
                 }

Mage.Server/src/main/java/mage/server/UserManager.java

@@ -42,9 +42,10 @@ import java.util.concurrent.*;
  *
  * @author BetaSteward_at_googlemail.com
  */
-public class UserManager {
+public enum  UserManager {
+    instance;
 
-    protected static final ScheduledExecutorService expireExecutor = Executors.newSingleThreadScheduledExecutor();
+    protected final ScheduledExecutorService expireExecutor = Executors.newSingleThreadScheduledExecutor();
 
     private static final Logger LOGGER = Logger.getLogger(UserManager.class);
 
@@ -53,13 +54,7 @@ public class UserManager {
 
     private static final ExecutorService USER_EXECUTOR = ThreadExecutor.getInstance().getCallExecutor();
 
-    private static final UserManager INSTANCE = new UserManager();
+    UserManager() {
-
-    public static UserManager getInstance() {
-        return INSTANCE;
-    }
-
-    private UserManager() {
         expireExecutor.scheduleAtFixedRate(this::checkExpired, 60, 60, TimeUnit.SECONDS);
     }
 
@@ -112,7 +107,7 @@ public class UserManager {
             if (user != null) {
                 user.setSessionId(""); // Session will be set again with new id if user reconnects
             }
-            ChatManager.getInstance().removeUser(userId, reason);
+            ChatManager.instance.removeUser(userId, reason);
         }
     }
 

Mage.Server/src/main/java/mage/server/challenge/ChallengeManager.java

@@ -14,10 +14,10 @@ import mage.game.match.Match;
  */
 public class ChallengeManager {
 
-    public static final ChallengeManager fInstance = new ChallengeManager();
+    public static final ChallengeManager instance = new ChallengeManager();
 
     public static ChallengeManager getInstance() {
-        return fInstance;
+        return instance;
     }
 
     public void prepareChallenge(UUID playerId, Match match) {

Mage.Server/src/main/java/mage/server/draft/DraftController.java

@@ -121,7 +121,7 @@ public class DraftController {
         UUID playerId = userPlayerMap.get(userId);
         DraftSession draftSession = new DraftSession(draft, userId, playerId);
         draftSessions.put(playerId, draftSession);
-        UserManager.getInstance().getUser(userId).ifPresent(user-> {
+        UserManager.instance.getUser(userId).ifPresent(user-> {
                     user.addDraft(playerId, draftSession);
                     logger.debug("User " + user.getName() + " has joined draft " + draft.getId());
                     draft.getPlayer(playerId).setJoined();
@@ -187,8 +187,8 @@ public class DraftController {
             draftSession.draftOver();
             draftSession.removeDraft();
         }
-        TableManager.getInstance().endDraft(tableId, draft);
+        TableManager.instance.endDraft(tableId, draft);
-        DraftManager.getInstance().removeDraft(draft.getId());
+        DraftManager.instance.removeDraft(draft.getId());
     }
 
     public void kill(UUID userId) {

Mage.Server/src/main/java/mage/server/draft/DraftManager.java

@@ -38,14 +38,8 @@ import mage.view.DraftPickView;
  *
  * @author BetaSteward_at_googlemail.com
  */
-public class DraftManager {
+public enum DraftManager {
-    private static final DraftManager INSTANCE = new DraftManager();
+    instance;
-
-    public static DraftManager getInstance() {
-        return INSTANCE;
-    }
-
-    private DraftManager() {}
 
     private final ConcurrentHashMap<UUID, DraftController> draftControllers = new ConcurrentHashMap<>();
 

Mage.Server/src/main/java/mage/server/draft/DraftSession.java

@@ -71,7 +71,7 @@ public class DraftSession {
 
     public boolean init() {
         if (!killed) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             if (user.isPresent()) {
                 if (futureTimeout != null && !futureTimeout.isDone()) {
                     int remaining = (int) futureTimeout.getDelay(TimeUnit.SECONDS);
@@ -85,7 +85,7 @@ public class DraftSession {
 
     public void update() {
         if (!killed) {
-            UserManager.getInstance()
+            UserManager.instance
                     .getUser(userId).
                     ifPresent(user -> user.fireCallback(
                             new ClientCallback("draftUpdate", draft.getId(), getDraftView())));
@@ -96,7 +96,7 @@ public class DraftSession {
     //
     public void inform(final String message) {
         if (!killed) {
-            UserManager.getInstance()
+            UserManager.instance
                     .getUser(userId)
                     .ifPresent(user -> user.fireCallback(new ClientCallback("draftInform", draft.getId(), new DraftClientMessage(getDraftView(), message))));
         }
@@ -105,7 +105,7 @@ public class DraftSession {
 
     public void draftOver() {
         if (!killed) {
-            UserManager.getInstance()
+            UserManager.instance
                     .getUser(userId)
                     .ifPresent(user -> user.fireCallback(new ClientCallback("draftOver", draft.getId())));
 
@@ -115,7 +115,7 @@ public class DraftSession {
     public void pickCard(int timeout) {
         if (!killed) {
             setupTimeout(timeout);
-            UserManager.getInstance()
+            UserManager.instance
                     .getUser(userId)
                     .ifPresent(user -> user.fireCallback(new ClientCallback("draftPick", draft.getId(), new DraftClientMessage(getDraftPickView(timeout)))));
 
@@ -126,7 +126,7 @@ public class DraftSession {
         cancelTimeout();
         if (seconds > 0) {
             futureTimeout = timeoutExecutor.schedule(
-                    () -> DraftManager.getInstance().timeout(draft.getId(), userId),
+                    () -> DraftManager.instance.timeout(draft.getId(), userId),
                     seconds, TimeUnit.SECONDS
             );
         }
@@ -140,7 +140,7 @@ public class DraftSession {
 
     protected void handleRemoteException(RemoteException ex) {
         logger.fatal("DraftSession error ", ex);
-        DraftManager.getInstance().kill(draft.getId(), userId);
+        DraftManager.instance.kill(draft.getId(), userId);
     }
 
     public void setKilled() {
@@ -156,7 +156,7 @@ public class DraftSession {
     }
 
     public void removeDraft() {
-        UserManager.getInstance().getUser(userId).ifPresent(user -> user.removeDraft(playerId));
+        UserManager.instance.getUser(userId).ifPresent(user -> user.removeDraft(playerId));
 
     }
 

Mage.Server/src/main/java/mage/server/game/GameController.java

@@ -119,10 +119,10 @@ public class GameController implements GameCallback {
     public GameController(Game game, ConcurrentHashMap<UUID, UUID> userPlayerMap, UUID tableId, UUID choosingPlayerId, GameOptions gameOptions) {
         gameSessionId = UUID.randomUUID();
         this.userPlayerMap = userPlayerMap;
-        chatId = ChatManager.getInstance().createChatSession("Game " + game.getId());
+        chatId = ChatManager.instance.createChatSession("Game " + game.getId());
         this.userReqestingRollback = null;
         this.game = game;
-        this.game.setSaveGame(ConfigSettings.getInstance().isSaveGameActivated());
+        this.game.setSaveGame(ConfigSettings.instance.isSaveGameActivated());
         this.tableId = tableId;
         this.choosingPlayerId = choosingPlayerId;
         this.gameOptions = gameOptions;
@@ -141,7 +141,7 @@ public class GameController implements GameCallback {
         for (GameSessionPlayer gameSessionPlayer : gameSessions.values()) {
             gameSessionPlayer.cleanUp();
         }
-        ChatManager.getInstance().destroyChatSession(chatId);
+        ChatManager.instance.destroyChatSession(chatId);
         for (PriorityTimer priorityTimer : timers.values()) {
             priorityTimer.cancel();
         }
@@ -158,11 +158,11 @@ public class GameController implements GameCallback {
                                 updateGame();
                                 break;
                             case INFO:
-                                ChatManager.getInstance().broadcast(chatId, "", event.getMessage(), MessageColor.BLACK, true, MessageType.GAME, null);
+                                ChatManager.instance.broadcast(chatId, "", event.getMessage(), MessageColor.BLACK, true, MessageType.GAME, null);
                                 logger.trace(game.getId() + " " + event.getMessage());
                                 break;
                             case STATUS:
-                                ChatManager.getInstance().broadcast(chatId, "", event.getMessage(), MessageColor.ORANGE, event.getWithTime(), MessageType.GAME, null);
+                                ChatManager.instance.broadcast(chatId, "", event.getMessage(), MessageColor.ORANGE, event.getWithTime(), MessageType.GAME, null);
                                 logger.trace(game.getId() + " " + event.getMessage());
                                 break;
                             case ERROR:
@@ -305,7 +305,7 @@ public class GameController implements GameCallback {
 
     public void join(UUID userId) {
         UUID playerId = userPlayerMap.get(userId);
-        Optional<User> user = UserManager.getInstance().getUser(userId);
+        Optional<User> user = UserManager.instance.getUser(userId);
         if (userId == null || playerId == null) {
             logger.fatal("Join game failed!");
             logger.fatal("- gameId: " + game.getId());
@@ -332,7 +332,7 @@ public class GameController implements GameCallback {
         }
         user.get().addGame(playerId, gameSession);
         logger.debug("Player " + player.getName() + ' ' + playerId + " has " + joinType + " gameId: " + game.getId());
-        ChatManager.getInstance().broadcast(chatId, "", game.getPlayer(playerId).getLogName() + " has " + joinType + " the game", MessageColor.ORANGE, true, MessageType.GAME, null);
+        ChatManager.instance.broadcast(chatId, "", game.getPlayer(playerId).getLogName() + " has " + joinType + " the game", MessageColor.ORANGE, true, MessageType.GAME, null);
         checkStart();
     }
 
@@ -356,10 +356,10 @@ public class GameController implements GameCallback {
                         if (gameSessions.get(player.getId()) == null) {
                             // join the game because player has not joined are was removed because of disconnect
                             user.removeConstructing(player.getId());
-                            GameManager.getInstance().joinGame(game.getId(), user.getId());
+                            GameManager.instance.joinGame(game.getId(), user.getId());
                             logger.debug("Player " + player.getName() + " (disconnected) has joined gameId: " + game.getId());
                         }
-                        ChatManager.getInstance().broadcast(chatId, player.getName(), user.getPingInfo() + " is pending to join the game", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
+                        ChatManager.instance.broadcast(chatId, player.getName(), user.getPingInfo() + " is pending to join the game", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
                         if (user.getSecondsDisconnected() > 240) {
                             // Cancel player join possibility lately after 4 minutes
                             logger.debug("Player " + player.getName() + " - canceled game (after 240 seconds) gameId: " + game.getId());
@@ -379,7 +379,7 @@ public class GameController implements GameCallback {
     private Optional<User> getUserByPlayerId(UUID playerId) {
         for (Map.Entry<UUID, UUID> entry : userPlayerMap.entrySet()) {
             if (entry.getValue().equals(playerId)) {
-                return UserManager.getInstance().getUser(entry.getKey());
+                return UserManager.instance.getUser(entry.getKey());
             }
         }
         return Optional.empty();
@@ -418,19 +418,19 @@ public class GameController implements GameCallback {
             // You can't watch a game if you already watch it
             return;
         }
-        UserManager.getInstance().getUser(userId).ifPresent(user -> {
+        UserManager.instance.getUser(userId).ifPresent(user -> {
             GameSessionWatcher gameWatcher = new GameSessionWatcher(userId, game, false);
             watchers.put(userId, gameWatcher);
             gameWatcher.init();
             user.addGameWatchInfo(game.getId());
-            ChatManager.getInstance().broadcast(chatId, user.getName(), " has started watching", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
+            ChatManager.instance.broadcast(chatId, user.getName(), " has started watching", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
         });
     }
 
     public void stopWatching(UUID userId) {
         watchers.remove(userId);
-        UserManager.getInstance().getUser(userId).ifPresent(user -> {
+        UserManager.instance.getUser(userId).ifPresent(user -> {
-            ChatManager.getInstance().broadcast(chatId, user.getName(), " has stopped watching", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
+            ChatManager.instance.broadcast(chatId, user.getName(), " has stopped watching", MessageColor.BLUE, true, ChatMessage.MessageType.STATUS, null);
         });
     }
 
@@ -599,7 +599,7 @@ public class GameController implements GameCallback {
                                 gameSession.requestPermissionToSeeHandCards(userIdRequester);
                             } else {
                                 // player does not allow the request
-                                UserManager.getInstance().getUser(userIdRequester).ifPresent(requester -> {
+                                UserManager.instance.getUser(userIdRequester).ifPresent(requester -> {
                                     requester.showUserMessage("Request to show hand cards", "Player " + grantingPlayer.getName() + " does not allow to request to show hand cards!");
                                 });
                             }
@@ -611,7 +611,7 @@ public class GameController implements GameCallback {
                 }
             } else {
                 // user can already see the cards
-                UserManager.getInstance().getUser(userIdRequester).ifPresent(requester -> {
+                UserManager.instance.getUser(userIdRequester).ifPresent(requester -> {
                     requester.showUserMessage("Request to show hand cards", "You can see already the hand cards of player " + grantingPlayer.getName() + '!');
                 });
 
@@ -653,8 +653,8 @@ public class GameController implements GameCallback {
         if (player != null) {
             String sb = player.getLogName()
                     + " has timed out (player had priority and was not active for "
-                    + ConfigSettings.getInstance().getMaxSecondsIdle() + " seconds ) - Auto concede.";
+                    + ConfigSettings.instance.getMaxSecondsIdle() + " seconds ) - Auto concede.";
-            ChatManager.getInstance().broadcast(chatId, "", sb, MessageColor.BLACK, true, MessageType.STATUS, null);
+            ChatManager.instance.broadcast(chatId, "", sb, MessageColor.BLACK, true, MessageType.STATUS, null);
             game.idleTimeout(playerId);
         }
     }
@@ -667,7 +667,7 @@ public class GameController implements GameCallback {
         for (final GameSessionWatcher gameWatcher : watchers.values()) {
             gameWatcher.gameOver(message);
         }
-        TableManager.getInstance().endGame(tableId);
+        TableManager.instance.endGame(tableId);
     }
 
     public UUID getSessionId() {
@@ -718,7 +718,7 @@ public class GameController implements GameCallback {
     }
 
     private synchronized void endGameInfo() {
-        Table table = TableManager.getInstance().getTable(tableId);
+        Table table = TableManager.instance.getTable(tableId);
         if (table != null) {
             if (table.getMatch() != null) {
                 for (final GameSessionPlayer gameSession : gameSessions.values()) {
@@ -967,7 +967,7 @@ public class GameController implements GameCallback {
         cancelTimeout();
         futureTimeout = timeoutIdleExecutor.schedule(
                 () -> idleTimeout(playerId),
-                Main.isTestMode() ? 3600 : ConfigSettings.getInstance().getMaxSecondsIdle(),
+                Main.isTestMode() ? 3600 : ConfigSettings.instance.getMaxSecondsIdle(),
                 TimeUnit.SECONDS
         );
     }

Mage.Server/src/main/java/mage/server/game/GameManager.java

@@ -41,14 +41,8 @@ import mage.view.GameView;
  *
  * @author BetaSteward_at_googlemail.com
  */
-public class GameManager {
+public enum GameManager {
-    private static final GameManager INSTANCE = new GameManager();
+    instance;
-
-    public static GameManager getInstance() {
-        return INSTANCE;
-    }
-
-    private GameManager() {}
 
     private final ConcurrentHashMap<UUID, GameController> gameControllers = new ConcurrentHashMap<>();
 

Mage.Server/src/main/java/mage/server/game/GameSessionPlayer.java

@@ -68,14 +68,14 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void ask(final String question, final Map<String, Serializable> options) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameAsk", game.getId(), new GameClientMessage(getGameView(), question, options)))
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameAsk", game.getId(), new GameClientMessage(getGameView(), question, options)))
             );
         }
     }
 
     public void target(final String question, final CardsView cardView, final Set<UUID> targets, final boolean required, final Map<String, Serializable> options) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> {
+            UserManager.instance.getUser(userId).ifPresent(user -> {
                 user.fireCallback(new ClientCallback("gameTarget", game.getId(), new GameClientMessage(getGameView(), question, cardView, targets, required, options)));
             });
 
@@ -84,13 +84,13 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void select(final String message, final Map<String, Serializable> options) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameSelect", game.getId(), new GameClientMessage(getGameView(), message, options))));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameSelect", game.getId(), new GameClientMessage(getGameView(), message, options))));
         }
     }
 
     public void chooseAbility(final AbilityPickerView abilities) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user
+            UserManager.instance.getUser(userId).ifPresent(user
                     -> user.fireCallback(new ClientCallback("gameChooseAbility", game.getId(), abilities)));
         }
 
@@ -98,7 +98,7 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void choosePile(final String message, final CardsView pile1, final CardsView pile2) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user
+            UserManager.instance.getUser(userId).ifPresent(user
                     -> user.fireCallback(new ClientCallback("gameChoosePile", game.getId(), new GameClientMessage(message, pile1, pile2))));
         }
 
@@ -106,7 +106,7 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void chooseChoice(final Choice choice) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user
+            UserManager.instance.getUser(userId).ifPresent(user
                     -> user.fireCallback(new ClientCallback("gameChooseChoice", game.getId(), new GameClientMessage(choice))));
         }
 
@@ -114,14 +114,14 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void playMana(final String message, final Map<String, Serializable> options) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user
+            UserManager.instance.getUser(userId).ifPresent(user
                     -> user.fireCallback(new ClientCallback("gamePlayMana", game.getId(), new GameClientMessage(getGameView(), message, options))));
         }
     }
 
     public void playXMana(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user
+            UserManager.instance.getUser(userId).ifPresent(user
                     -> user.fireCallback(new ClientCallback("gamePlayXMana", game.getId(), new GameClientMessage(getGameView(), message))));
 
         }
@@ -129,7 +129,7 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void getAmount(final String message, final int min, final int max) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> {
+            UserManager.instance.getUser(userId).ifPresent(user -> {
                 user.fireCallback(new ClientCallback("gameSelectAmount", game.getId(), new GameClientMessage(message, min, max)));
             });
         }
@@ -137,15 +137,15 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void endGameInfo(Table table) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("endGameInfo", game.getId(), getGameEndView(playerId, table))));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("endGameInfo", game.getId(), getGameEndView(playerId, table))));
 
         }
     }
 
     public void requestPermissionToRollbackTurn(UUID requestingUserId, int numberTurns) {
         if (!killed) {
-            Optional<User> requestingUser = UserManager.getInstance().getUser(requestingUserId);
+            Optional<User> requestingUser = UserManager.instance.getUser(requestingUserId);
-            Optional<User> requestedUser = UserManager.getInstance().getUser(userId);
+            Optional<User> requestedUser = UserManager.instance.getUser(userId);
             if (requestedUser.isPresent() && requestingUser.isPresent()) {
                 String message;
                 switch (numberTurns) {
@@ -171,8 +171,8 @@ public class GameSessionPlayer extends GameSessionWatcher {
 
     public void requestPermissionToSeeHandCards(UUID watcherId) {
         if (!killed) {
-            Optional<User> watcher = UserManager.getInstance().getUser(watcherId);
+            Optional<User> watcher = UserManager.instance.getUser(watcherId);
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             if (user.isPresent() && watcher.isPresent()) {
                 UserRequestMessage userRequestMessage = new UserRequestMessage(
                         "User request",
@@ -241,7 +241,7 @@ public class GameSessionPlayer extends GameSessionWatcher {
     }
 
     public void removeGame() {
-        UserManager.getInstance().getUser(userId).ifPresent(user -> user.removeGame(playerId));
+        UserManager.instance.getUser(userId).ifPresent(user -> user.removeGame(playerId));
 
     }
 

Mage.Server/src/main/java/mage/server/game/GameSessionWatcher.java

@@ -65,7 +65,7 @@ public class GameSessionWatcher {
 
     public boolean init() {
         if (!killed) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             if (user.isPresent()) {
                 user.get().fireCallback(new ClientCallback("gameInit", game.getId(), getGameView()));
                 return true;
@@ -76,28 +76,28 @@ public class GameSessionWatcher {
 
     public void update() {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameUpdate", game.getId(), getGameView())));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameUpdate", game.getId(), getGameView())));
         }
 
     }
 
     public void inform(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameInform", game.getId(), new GameClientMessage(getGameView(), message))));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameInform", game.getId(), new GameClientMessage(getGameView(), message))));
         }
 
     }
 
     public void informPersonal(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameInformPersonal", game.getId(), new GameClientMessage(getGameView(), message))));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameInformPersonal", game.getId(), new GameClientMessage(getGameView(), message))));
         }
 
     }
 
     public void gameOver(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> {
+            UserManager.instance.getUser(userId).ifPresent(user -> {
                 user.removeGameWatchInfo(game.getId());
                 user.fireCallback(new ClientCallback("gameOver", game.getId(), message));
             });
@@ -113,7 +113,7 @@ public class GameSessionWatcher {
 
     public void gameError(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameError", game.getId(), message)));
+            UserManager.instance.getUser(userId).ifPresent(user -> user.fireCallback(new ClientCallback("gameError", game.getId(), message)));
 
         }
     }

Mage.Server/src/main/java/mage/server/game/GamesRoomImpl.java

@@ -100,7 +100,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
             } else {
                 // more since 50 matches finished since this match so remove it
                 if (table.isTournament()) {
-                    TournamentManager.getInstance().removeTournament(table.getTournament().getId());
+                    TournamentManager.instance.removeTournament(table.getTournament().getId());
                 }
                 this.removeTable(table.getId());
             }
@@ -108,7 +108,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
         tableView = tableList;
         matchView = matchList;
         List<UsersView> users = new ArrayList<>();
-        for (User user : UserManager.getInstance().getUsers()) {
+        for (User user : UserManager.instance.getUsers()) {
             try {
                 users.add(new UsersView(user.getUserData().getFlagName(), user.getName(),
                         user.getMatchHistory(), user.getMatchQuitRatio(), user.getTourneyHistory(),
@@ -135,9 +135,9 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
         users.sort((one, two) -> one.getUserName().compareToIgnoreCase(two.getUserName()));
         List<RoomUsersView> roomUserInfo = new ArrayList<>();
         roomUserInfo.add(new RoomUsersView(users,
-                GameManager.getInstance().getNumberActiveGames(),
+                GameManager.instance.getNumberActiveGames(),
                 ThreadExecutor.getInstance().getActiveThreads(ThreadExecutor.getInstance().getGameExecutor()),
-                ConfigSettings.getInstance().getMaxGameThreads()
+                ConfigSettings.instance.getMaxGameThreads()
         ));
         roomUsersView = roomUserInfo;
     }
@@ -150,7 +150,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
     @Override
     public boolean joinTable(UUID userId, UUID tableId, String name, String playerType, int skill, DeckCardLists deckList, String password) throws MageException {
         if (tables.containsKey(tableId)) {
-            return TableManager.getInstance().joinTable(userId, tableId, name, playerType, skill, deckList, password);
+            return TableManager.instance.joinTable(userId, tableId, name, playerType, skill, deckList, password);
         } else {
             return false;
         }
@@ -158,7 +158,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
 
     @Override
     public TableView createTable(UUID userId, MatchOptions options) {
-        Table table = TableManager.getInstance().createTable(this.getRoomId(), userId, options);
+        Table table = TableManager.instance.createTable(this.getRoomId(), userId, options);
         tables.put(table.getId(), table);
         return new TableView(table);
     }
@@ -166,7 +166,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
     @Override
     public boolean joinTournamentTable(UUID userId, UUID tableId, String name, String playerType, int skill, DeckCardLists deckList, String password) throws GameException {
         if (tables.containsKey(tableId)) {
-            return TableManager.getInstance().joinTournament(userId, tableId, name, playerType, skill, deckList, password);
+            return TableManager.instance.joinTournament(userId, tableId, name, playerType, skill, deckList, password);
         } else {
             return false;
         }
@@ -174,7 +174,7 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
 
     @Override
     public TableView createTournamentTable(UUID userId, TournamentOptions options) {
-        Table table = TableManager.getInstance().createTournamentTable(this.getRoomId(), userId, options);
+        Table table = TableManager.instance.createTournamentTable(this.getRoomId(), userId, options);
         tables.put(table.getId(), table);
         return new TableView(table);
     }
@@ -206,12 +206,12 @@ public class GamesRoomImpl extends RoomImpl implements GamesRoom, Serializable {
 
     @Override
     public void leaveTable(UUID userId, UUID tableId) {
-        TableManager.getInstance().leaveTable(userId, tableId);
+        TableManager.instance.leaveTable(userId, tableId);
     }
 
     @Override
     public boolean watchTable(UUID userId, UUID tableId) throws MageException {
-        return TableManager.getInstance().watchTable(userId, tableId);
+        return TableManager.instance.watchTable(userId, tableId);
     }
 
     @Override

Mage.Server/src/main/java/mage/server/game/GamesRoomManager.java

@@ -32,22 +32,16 @@ import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- *
  * @author BetaSteward_at_googlemail.com
  */
-public class GamesRoomManager {
+public enum GamesRoomManager {
-
+    instance;
-    private static final GamesRoomManager INSTANCE = new GamesRoomManager();
-//    private static final Logger logger = Logger.getLogger(GamesRoomManager.class);
 
     private final ConcurrentHashMap<UUID, GamesRoom> rooms = new ConcurrentHashMap<>();
     private final UUID mainRoomId;
 
-    public static GamesRoomManager getInstance() {
-        return INSTANCE;
-    }
 
-    private GamesRoomManager() {
+    GamesRoomManager() {
         GamesRoom mainRoom = new GamesRoomImpl();
         mainRoomId = mainRoom.getRoomId();
         rooms.put(mainRoomId, mainRoom);

Mage.Server/src/main/java/mage/server/game/ReplayManager.java

@@ -36,21 +36,15 @@ import mage.server.UserManager;
  *
  * @author BetaSteward_at_googlemail.com
  */
-public class ReplayManager {
+public enum ReplayManager {
-    private static final ReplayManager INSTANCE = new ReplayManager();
+    instance;
-
-    public static ReplayManager getInstance() {
-        return INSTANCE;
-    }
-
-    private ReplayManager() {}
 
     private final ConcurrentHashMap<String, ReplaySession> replaySessions = new ConcurrentHashMap<>();
 
     public void replayGame(UUID gameId, UUID userId) {
         ReplaySession replaySession = new ReplaySession(gameId, userId);
         replaySessions.put(gameId.toString() + userId.toString(), replaySession);
-        UserManager.getInstance().getUser(userId).ifPresent(user->user.ccReplayGame(gameId));
+        UserManager.instance.getUser(userId).ifPresent(user->user.ccReplayGame(gameId));
     }
 
     public void startReplay(UUID gameId, UUID userId) {

Mage.Server/src/main/java/mage/server/game/ReplaySession.java

@@ -51,7 +51,7 @@ public class ReplaySession implements GameCallback {
 
     public void replay() {
         replay.start();
-        UserManager.getInstance().getUser(userId).ifPresent(user ->
+        UserManager.instance.getUser(userId).ifPresent(user ->
                 user.fireCallback(new ClientCallback("replayInit", replay.getGame().getId(), new GameView(replay.next(), replay.getGame(), null, null))));
 
     }
@@ -77,17 +77,17 @@ public class ReplaySession implements GameCallback {
 
     @Override
     public void gameResult(final String result) {
-        UserManager.getInstance().getUser(userId).ifPresent(user ->
+        UserManager.instance.getUser(userId).ifPresent(user ->
                 user.fireCallback(new ClientCallback("replayDone", replay.getGame().getId(), result)));
 
-        ReplayManager.getInstance().endReplay(replay.getGame().getId(), userId);
+        ReplayManager.instance.endReplay(replay.getGame().getId(), userId);
     }
 
     private void updateGame(final GameState state, Game game) {
         if (state == null) {
             gameResult("game ended");
         } else {
-            UserManager.getInstance().getUser(userId).ifPresent(user ->
+            UserManager.instance.getUser(userId).ifPresent(user ->
                     user.fireCallback(new ClientCallback("replayUpdate", replay.getGame().getId(), new GameView(state, game, null, null))));
 
         }

Mage.Server/src/main/java/mage/server/record/TableRecorderImpl.java

@@ -17,6 +17,6 @@ public class TableRecorderImpl implements TableRecorder {
     public void record(Table table) {
         TableProto proto = table.toProto();
         TableRecordRepository.instance.add(new TableRecord(proto, proto.getEndTimeMs()));
-        UserManager.getInstance().updateUserHistory();
+        UserManager.instance.updateUserHistory();
     }
 }

Mage.Server/src/main/java/mage/server/tournament/TournamentController.java

@@ -77,7 +77,7 @@ public class TournamentController {
 
     public TournamentController(Tournament tournament, ConcurrentHashMap<UUID, UUID> userPlayerMap, UUID tableId) {
         this.userPlayerMap = userPlayerMap;
-        chatId = ChatManager.getInstance().createChatSession("Tournament " + tournament.getId());
+        chatId = ChatManager.instance.createChatSession("Tournament " + tournament.getId());
         this.tournament = tournament;
         this.tableId = tableId;
         init();
@@ -91,7 +91,7 @@ public class TournamentController {
                             checkPlayersState();
                             break;
                         case INFO:
-                            ChatManager.getInstance().broadcast(chatId, "", event.getMessage(), MessageColor.BLACK, true, MessageType.STATUS, null);
+                            ChatManager.instance.broadcast(chatId, "", event.getMessage(), MessageColor.BLACK, true, MessageType.STATUS, null);
                             logger.debug(tournament.getId() + " " + event.getMessage());
                             break;
                         case START_DRAFT:
@@ -146,7 +146,7 @@ public class TournamentController {
             if (!player.getPlayer().isHuman()) {
                 player.setJoined();
                 logger.debug("player " + player.getPlayer().getId() + " has joined tournament " + tournament.getId());
-                ChatManager.getInstance().broadcast(chatId, "", player.getPlayer().getLogName() + " has joined the tournament", MessageColor.BLACK, true, MessageType.STATUS, null);
+                ChatManager.instance.broadcast(chatId, "", player.getPlayer().getLogName() + " has joined the tournament", MessageColor.BLACK, true, MessageType.STATUS, null);
             }
         }
         checkStart();
@@ -156,7 +156,7 @@ public class TournamentController {
         UUID playerId = userPlayerMap.get(userId);
         if (playerId == null) {
             if (logger.isDebugEnabled()) {
-                UserManager.getInstance().getUser(userId).ifPresent(user ->
+                UserManager.instance.getUser(userId).ifPresent(user ->
                         logger.debug(user.getName() + " shows tournament panel  tournamentId: " + tournament.getId()));
 
             }
@@ -169,14 +169,14 @@ public class TournamentController {
         // first join of player
         TournamentSession tournamentSession = new TournamentSession(tournament, userId, tableId, playerId);
         tournamentSessions.put(playerId, tournamentSession);
-        Optional<User> _user = UserManager.getInstance().getUser(userId);
+        Optional<User> _user = UserManager.instance.getUser(userId);
         if (_user.isPresent()) {
             User user = _user.get();
             user.addTournament(playerId, tournament.getId());
             TournamentPlayer player = tournament.getPlayer(playerId);
             player.setJoined();
             logger.debug("player " + player.getPlayer().getName() + " - client has joined tournament " + tournament.getId());
-            ChatManager.getInstance().broadcast(chatId, "", player.getPlayer().getLogName() + " has joined the tournament", MessageColor.BLACK, true, MessageType.STATUS, null);
+            ChatManager.instance.broadcast(chatId, "", player.getPlayer().getLogName() + " has joined the tournament", MessageColor.BLACK, true, MessageType.STATUS, null);
             checkStart();
         } else {
             logger.error("User not found  userId: " + userId + "   tournamentId: " + tournament.getId());
@@ -235,15 +235,15 @@ public class TournamentController {
             tournamentSession.tournamentOver();
         }
         this.tournamentSessions.clear();
-        TableManager.getInstance().endTournament(tableId, tournament);
+        TableManager.instance.endTournament(tableId, tournament);
         tournament.cleanUpOnTournamentEnd();
 
     }
 
     private void startMatch(TournamentPairing pair, MatchOptions matchOptions) {
         try {
-            TableManager tableManager = TableManager.getInstance();
+            TableManager tableManager = TableManager.instance;
-            Table table = tableManager.createTable(GamesRoomManager.getInstance().getMainRoomId(), matchOptions);
+            Table table = tableManager.createTable(GamesRoomManager.instance.getMainRoomId(), matchOptions);
             table.setTournamentSubTable(true);
             table.setTournament(tournament);
             table.setState(TableState.WAITING);
@@ -266,8 +266,8 @@ public class TournamentController {
 
     private void startMultiplayerMatch(MultiplayerRound round, MatchOptions matchOptions) {
         try {
-            TableManager tableManager = TableManager.getInstance();
+            TableManager tableManager = TableManager.instance;
-            Table table = tableManager.createTable(GamesRoomManager.getInstance().getMainRoomId(), matchOptions);
+            Table table = tableManager.createTable(GamesRoomManager.instance.getMainRoomId(), matchOptions);
             table.setTournamentSubTable(true);
             table.setTournament(tournament);
             table.setState(TableState.WAITING);
@@ -290,16 +290,16 @@ public class TournamentController {
     }
 
     private void startDraft(Draft draft) {
-        TableManager.getInstance().startDraft(tableId, draft);
+        TableManager.instance.startDraft(tableId, draft);
     }
 
     private void construct() {
-        TableManager.getInstance().construct(tableId);
+        TableManager.instance.construct(tableId);
     }
 
     private void initTournament() {
-        if (TableManager.getInstance().getTable(tableId).getState() != TableState.DUELING) {
+        if (TableManager.instance.getTable(tableId).getState() != TableState.DUELING) {
-            TableManager.getInstance().initTournament(tableId);
+            TableManager.instance.initTournament(tableId);
         }
     }
 
@@ -307,7 +307,7 @@ public class TournamentController {
         if (tournamentSessions.containsKey(playerId)) {
             TournamentSession tournamentSession = tournamentSessions.get(playerId);
             tournamentSession.construct(timeout);
-            UserManager.getInstance().getUser(getPlayerUserId(playerId)).get().addConstructing(playerId, tournamentSession);
+            UserManager.instance.getUser(getPlayerUserId(playerId)).get().addConstructing(playerId, tournamentSession);
             TournamentPlayer player = tournament.getPlayer(playerId);
             player.setState(TournamentPlayerState.CONSTRUCTING);
         }
@@ -318,7 +318,7 @@ public class TournamentController {
             TournamentPlayer player = tournament.getPlayer(playerId);
             if (player != null && !player.hasQuit()) {
                 tournamentSessions.get(playerId).submitDeck(deck);
-                ChatManager.getInstance().broadcast(chatId, "", player.getPlayer().getLogName() + " has submitted his or her tournament deck", MessageColor.BLACK, true, MessageType.STATUS, SoundToPlay.PlayerSubmittedDeck);
+                ChatManager.instance.broadcast(chatId, "", player.getPlayer().getLogName() + " has submitted his or her tournament deck", MessageColor.BLACK, true, MessageType.STATUS, SoundToPlay.PlayerSubmittedDeck);
             }
         }
     }
@@ -336,7 +336,7 @@ public class TournamentController {
                 tournament.autoSubmit(userPlayerMap.get(userId), tournamentPlayer.generateDeck());
             } else {
                 StringBuilder sb = new StringBuilder();
-                UserManager.getInstance().getUser(userId).ifPresent(user ->
+                UserManager.instance.getUser(userId).ifPresent(user ->
                         sb.append(user.getName()));
 
                 sb.append(" - no deck found for auto submit");
@@ -378,18 +378,18 @@ public class TournamentController {
             if (tournament.isDoneConstructing()) {
                 info = new StringBuilder("during round ").append(tournament.getRounds().size()).toString();
                 // quit active matches of that tournament
-                TableManager.getInstance().userQuitTournamentSubTables(tournament.getId(), userId);
+                TableManager.instance.userQuitTournamentSubTables(tournament.getId(), userId);
                 status = TourneyQuitStatus.DURING_ROUND;
             } else if (tournamentPlayer.getState() == TournamentPlayerState.DRAFTING) {
                 info = "during Draft phase";
                 if (!checkToReplaceDraftPlayerByAi(userId, tournamentPlayer)) {
                     this.abortDraftTournament();
                 } else {
-                    DraftController draftController = DraftManager.getInstance().getController(tableId);
+                    DraftController draftController = DraftManager.instance.getController(tableId);
                     if (draftController != null) {
                         DraftSession draftSession = draftController.getDraftSession(playerId);
                         if (draftSession != null) {
-                            DraftManager.getInstance().kill(draftSession.getDraftId(), userId);
+                            DraftManager.instance.kill(draftSession.getDraftId(), userId);
                         }
                     }
                 }
@@ -404,7 +404,7 @@ public class TournamentController {
             tournamentPlayer.setQuit(info, status);
             tournament.quit(playerId);
             tournamentSession.quit();
-            ChatManager.getInstance().broadcast(chatId, "", tournamentPlayer.getPlayer().getLogName() + " has quit the tournament", MessageColor.BLACK, true, MessageType.STATUS, SoundToPlay.PlayerQuitTournament);
+            ChatManager.instance.broadcast(chatId, "", tournamentPlayer.getPlayer().getLogName() + " has quit the tournament", MessageColor.BLACK, true, MessageType.STATUS, SoundToPlay.PlayerQuitTournament);
         }
     }
 
@@ -418,8 +418,8 @@ public class TournamentController {
         }
         // replace player that quits with draft bot
         if (humans > 1) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
-            TableController tableController = TableManager.getInstance().getController(tableId);
+            TableController tableController = TableManager.instance.getController(tableId);
             if (tableController != null) {
                 String replacePlayerName = "Draftbot";
                 if (user.isPresent()) {
@@ -431,7 +431,7 @@ public class TournamentController {
                     user.get().removeTable(leavingPlayer.getPlayer().getId());
                     user.get().removeTournament(leavingPlayer.getPlayer().getId());
                 }
-                ChatManager.getInstance().broadcast(chatId, "", leavingPlayer.getPlayer().getLogName() + " was replaced by draftbot", MessageColor.BLACK, true, MessageType.STATUS, null);
+                ChatManager.instance.broadcast(chatId, "", leavingPlayer.getPlayer().getLogName() + " was replaced by draftbot", MessageColor.BLACK, true, MessageType.STATUS, null);
             }
             return true;
         }
@@ -453,7 +453,7 @@ public class TournamentController {
 
     private void abortDraftTournament() {
         tournament.setAbort(true);
-        DraftManager.getInstance().getController(tableId).abortDraft();
+        DraftManager.instance.getController(tableId).abortDraft();
     }
 
     public boolean isAbort() {
@@ -478,7 +478,7 @@ public class TournamentController {
     }
 
     public void cleanUpOnRemoveTournament() {
-        ChatManager.getInstance().destroyChatSession(chatId);
+        ChatManager.instance.destroyChatSession(chatId);
     }
 
     /**
@@ -496,7 +496,7 @@ public class TournamentController {
             if (tournamentPlayer != null) {
                 if (!tournamentPlayer.hasQuit()) {
                     if (tournamentPlayer.getPlayer().isHuman()) {
-                        Optional<User> user = UserManager.getInstance().getUser(entry.getKey());
+                        Optional<User> user = UserManager.instance.getUser(entry.getKey());
                         if (!user.isPresent()) {
                             logger.debug("Tournament user is missing but player active -> start quit - tournamentId: " + tournament.getId() + " state: " + tableState.toString());
                             // active tournament player but the user is no longer online

Mage.Server/src/main/java/mage/server/tournament/TournamentManager.java

@@ -30,25 +30,19 @@ package mage.server.tournament;
 
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
+
 import mage.cards.decks.Deck;
 import mage.game.tournament.Tournament;
 import mage.view.TournamentView;
 import org.apache.log4j.Logger;
 
 /**
- *
  * @author BetaSteward_at_googlemail.com
  */
-public class TournamentManager {
+public enum TournamentManager {
-
+    instance;
-    private static final TournamentManager INSTANCE = new TournamentManager();
-
     private final ConcurrentHashMap<UUID, TournamentController> controllers = new ConcurrentHashMap<>();
 
-    public static TournamentManager getInstance() {
-        return INSTANCE;
-    }
-
     public TournamentController getTournamentController(UUID tournamentId) {
         return controllers.get(tournamentId);
     }

Mage.Server/src/main/java/mage/server/tournament/TournamentSession.java

@@ -67,7 +67,7 @@ public class TournamentSession {
 
     public boolean init() {
         if (!killed) {
-            Optional<User> user = UserManager.getInstance().getUser(userId);
+            Optional<User> user = UserManager.instance.getUser(userId);
             if (user.isPresent()) {
                 user.get().fireCallback(new ClientCallback("tournamentInit", tournament.getId(), getTournamentView()));
                 return true;
@@ -78,7 +78,7 @@ public class TournamentSession {
 
     public void update() {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user ->
+            UserManager.instance.getUser(userId).ifPresent(user ->
                     user.fireCallback(new ClientCallback("tournamentUpdate", tournament.getId(), getTournamentView())));
 
         }
@@ -86,7 +86,7 @@ public class TournamentSession {
 
     public void gameOver(final String message) {
         if (!killed) {
-            UserManager.getInstance().getUser(userId).ifPresent(user ->
+            UserManager.instance.getUser(userId).ifPresent(user ->
                     user.fireCallback(new ClientCallback("tournamentOver", tournament.getId(), message)));
 
         }
@@ -95,7 +95,7 @@ public class TournamentSession {
     public void construct(int timeout) {
         if (!killed) {
             setupTimeout(timeout);
-            UserManager.getInstance().getUser(userId).ifPresent(user -> {
+            UserManager.instance.getUser(userId).ifPresent(user -> {
                 int remaining = (int) futureTimeout.getDelay(TimeUnit.SECONDS);
                 user.ccConstruct(tournament.getPlayer(playerId).getDeck(), tableId, remaining);
             });
@@ -128,7 +128,7 @@ public class TournamentSession {
             futureTimeout = timeoutExecutor.schedule(
                     () -> {
                         try {
-                            TournamentManager.getInstance().timeout(tournament.getId(), userId);
+                            TournamentManager.instance.timeout(tournament.getId(), userId);
                         } catch (Exception e) {
                             logger.fatal("TournamentSession error - userId " + userId + " tId " + tournament.getId(), e);
                         }
@@ -170,7 +170,7 @@ public class TournamentSession {
     }
 
     private void removeTournamentForUser() {
-        UserManager.getInstance().getUser(userId).ifPresent(user ->
+        UserManager.instance.getUser(userId).ifPresent(user ->
                 user.removeTournament(playerId));
 
 

Mage.Server/src/main/java/mage/server/util/ConfigSettings.java

@@ -33,27 +33,23 @@ import java.util.List;
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
 import javax.xml.bind.Unmarshaller;
+
 import mage.server.util.config.Config;
 import mage.server.util.config.GamePlugin;
 import mage.server.util.config.Plugin;
 import org.apache.log4j.Logger;
 
 /**
- *
  * @author BetaSteward_at_googlemail.com
  */
-public class ConfigSettings {
+public enum ConfigSettings {
-
+    instance;
-    private static final Logger logger = Logger.getLogger(ConfigSettings.class);
+    private final Logger logger = Logger.getLogger(ConfigSettings.class);
-    private static final ConfigSettings INSTANCE = new ConfigSettings();
 
     private Config config;
 
-    public static ConfigSettings getInstance() {
-        return INSTANCE;
-    }
 
-    private ConfigSettings() {
+    ConfigSettings() {
         try {
             JAXBContext jaxbContext = JAXBContext.newInstance("mage.server.util.config");
             Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();

Mage.Server/src/main/java/mage/server/util/ServerMessagesUtil.java

@@ -48,13 +48,11 @@ import java.util.concurrent.locks.ReentrantReadWriteLock;
  *
  * @author nantuko
  */
-public class ServerMessagesUtil {
+public enum ServerMessagesUtil {
-
+instance;
-    private static final ServerMessagesUtil instance = new ServerMessagesUtil();
-
     private static final Logger log = Logger.getLogger(ServerMessagesUtil.class);
     private static final String SERVER_MSG_TXT_FILE = "server.msg.txt";
-    private static ScheduledExecutorService updateExecutor;
+    private ScheduledExecutorService updateExecutor;
 
     private final List<String> messages = new ArrayList<>();
     private final ReadWriteLock lock = new ReentrantReadWriteLock();
@@ -73,14 +71,12 @@ public class ServerMessagesUtil {
         pathToExternalMessages = System.getProperty("messagesPath");
     }
 
-    public ServerMessagesUtil() {
+    ServerMessagesUtil() {
         updateExecutor = Executors.newSingleThreadScheduledExecutor();
         updateExecutor.scheduleAtFixedRate(this::reloadMessages, 5, 5 * 60, TimeUnit.SECONDS);
     }
 
-    public static ServerMessagesUtil getInstance() {
+
-        return instance;
-    }
 
     public List<String> getMessages() {
         lock.readLock().lock();

Mage.Server/src/main/java/mage/server/util/ThreadExecutor.java

@@ -42,7 +42,7 @@ public class ThreadExecutor {
 
     private static final ExecutorService callExecutor = Executors.newCachedThreadPool();
     private static final ExecutorService userExecutor = Executors.newCachedThreadPool();
-    private static final ExecutorService gameExecutor = Executors.newFixedThreadPool(ConfigSettings.getInstance().getMaxGameThreads());
+    private static final ExecutorService gameExecutor = Executors.newFixedThreadPool(ConfigSettings.instance.getMaxGameThreads());
     private static final ScheduledExecutorService timeoutExecutor = Executors.newScheduledThreadPool(4);
     private static final ScheduledExecutorService timeoutIdleExecutor = Executors.newScheduledThreadPool(4);
 

Mage.Sets/src/mage/cards/a/AbzanBeastmaster.java

@@ -54,7 +54,7 @@ public class AbzanBeastmaster extends CardImpl {
         // At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness.
         this.addAbility(new ConditionalTriggeredAbility(
                 new BeginningOfUpkeepTriggeredAbility(new DrawCardSourceControllerEffect(1), TargetController.YOU, false),
-                ControlsCreatureGreatestToughnessCondition.getInstance(),
+                ControlsCreatureGreatestToughnessCondition.instance,
                 "At the beginning of your upkeep, draw a card if you control the creature with the greatest toughness or tied for the greatest toughness."
         ));
     }

Mage.Sets/src/mage/cards/a/AetherFigment.java

@@ -61,7 +61,7 @@ public class AetherFigment extends CardImpl {
         // If Aether Figment was kicked, it enters the battlefield with two +1/+1 counters on it
         Ability ability = new EntersBattlefieldAbility(
                 new AddCountersSourceEffect(CounterType.P1P1.createInstance(2)),
-                KickedCondition.getInstance(),
+                KickedCondition.instance,
                 "If {this} was kicked, it enters the battlefield with two +1/+1 counters on it",
                 "");
         this.addAbility(ability);

Mage.Sets/src/mage/cards/a/AfflictedDeserter.java

@@ -61,7 +61,7 @@ public class AfflictedDeserter extends CardImpl {
         // At the beginning of each upkeep, if no spells were cast last turn, transform Afflicted Deserter.
         this.addAbility(new TransformAbility());
         TriggeredAbility ability = new BeginningOfUpkeepTriggeredAbility(new TransformSourceEffect(true), TargetController.ANY, false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, NoSpellsWereCastLastTurnCondition.getInstance(), TransformAbility.NO_SPELLS_TRANSFORM_RULE));
+        this.addAbility(new ConditionalTriggeredAbility(ability, NoSpellsWereCastLastTurnCondition.instance, TransformAbility.NO_SPELLS_TRANSFORM_RULE));
     }
 
     public AfflictedDeserter(final AfflictedDeserter card) {

Mage.Sets/src/mage/cards/a/AgonizingDemise.java

@@ -67,7 +67,7 @@ public class AgonizingDemise extends CardImpl {
         //If Agonizing Demise was kicked, it deals damage equal to that creature's power to the creature's controller.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new DamageTargetControllerEffect(new TargetPermanentPowerCount()),
-                KickedCondition.getInstance(),
+                KickedCondition.instance,
                 "If {this} was kicked, it deals damage equal to that creature's power to the creature's controller."));
         
     }

Mage.Sets/src/mage/cards/a/AidFromTheCowl.java

@@ -63,7 +63,7 @@ public class AidFromTheCowl extends CardImpl {
         // <i>Revolt</i> &mdash; At the beginning of your end step, if a permanent you controlled left the battlefield this turn,
         // reveal the top card of your library. If it is a permanent card, you may put it onto the battlefield. Otherwise, put it on the bottom of your library.
         TriggeredAbility ability = new BeginningOfYourEndStepTriggeredAbility(new AidFromTheCowlEffect(), false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, RevoltCondition.getInstance(), ruleText), new RevoltWatcher());
+        this.addAbility(new ConditionalTriggeredAbility(ability, RevoltCondition.instance, ruleText), new RevoltWatcher());
     }
 
     public AidFromTheCowl(final AidFromTheCowl card) {

Mage.Sets/src/mage/cards/a/AirdropAeronauts.java

@@ -60,7 +60,7 @@ public class AirdropAeronauts extends CardImpl {
 
         // <i>Revolt</i> &mdash; When Airdrop Aeronauts enters the battlefield, if a permanent you controlled left the battlefield this turn, you gain 5 life.
         Ability ability = new ConditionalTriggeredAbility(new EntersBattlefieldTriggeredAbility(
-                new GainLifeEffect(5), false), RevoltCondition.getInstance(),
+                new GainLifeEffect(5), false), RevoltCondition.instance,
                 "<i>Revolt</i> &mdash; When {this} enters the battlefield, if a permanent you controlled left"
                 + " the battlefield this turn, you gain 5 life."
         );

Mage.Sets/src/mage/cards/a/Aleatory.java

@@ -57,7 +57,7 @@ public class Aleatory extends CardImpl {
         super(ownerId,setInfo,new CardType[]{CardType.INSTANT},"{1}{R}");
 
         // Cast Aleatory only during combat after blockers are declared.
-        this.addAbility(new CastOnlyDuringPhaseStepSourceAbility(TurnPhase.COMBAT, AfterBlockersAreDeclaredCondition.getInstance()));
+        this.addAbility(new CastOnlyDuringPhaseStepSourceAbility(TurnPhase.COMBAT, AfterBlockersAreDeclaredCondition.instance));
 
         // Flip a coin. If you win the flip, target creature gets +1/+1 until end of turn.
         this.getSpellAbility().addEffect(new AleatoryEffect());

Mage.Sets/src/mage/cards/a/Aluren.java

@@ -102,7 +102,7 @@ class AlurenRuleEffect extends ContinuousEffectImpl {
         filter.add(new ConvertedManaCostPredicate(ComparisonType.LessThan, 4));
     }
     
-    static AlternativeCostSourceAbility alternativeCastingCostAbility = new AlternativeCostSourceAbility(null, SourceIsSpellCondition.getInstance(), null, filter,  true);
+    static AlternativeCostSourceAbility alternativeCastingCostAbility = new AlternativeCostSourceAbility(null, SourceIsSpellCondition.instance, null, filter,  true);
     
     public AlurenRuleEffect() {
         super(Duration.WhileOnBattlefield, Outcome.Detriment);

Mage.Sets/src/mage/cards/a/AngelOfDeliverance.java

@@ -73,7 +73,7 @@ public class AngelOfDeliverance extends CardImpl {
         // exile target creature an opponent controls.
         Ability ability = new ConditionalTriggeredAbility(
                 new AngelOfDeliveranceDealsDamageTriggeredAbility(),
-                new DeliriumCondition(),
+                DeliriumCondition.instance,
                 "<i>Delirium</i> &mdash; Whenever {this} deals damage, if there are four or more card types among cards in your graveyard, exile target creature an opponent controls"
         );
         ability.addTarget(new TargetCreaturePermanent(filter));

Mage.Sets/src/mage/cards/a/AngryMob.java

@@ -72,7 +72,7 @@ public class AngryMob extends CardImpl {
         PermanentsOnBattlefieldCount swamps = new PermanentsOnBattlefieldCount(filter);
         this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(
                 new BoostSourceEffect(swamps, swamps, Duration.WhileOnBattlefield),
-                MyTurnCondition.getInstance(),
+                MyTurnCondition.instance,
                 "As long as it's your turn, Angry Mob's power and toughness are each equal to 2 plus the number of Swamps your opponents control. As long as it's not your turn, Angry Mob's power and toughness are each 2")));
 
     }

Mage.Sets/src/mage/cards/a/AngusMackenzie.java

@@ -83,10 +83,10 @@ public class AngusMackenzie extends CardImpl {
 }
 
 class BeforeCombatDamageCondition implements Condition {
-    private static final BeforeCombatDamageCondition fInstance = new BeforeCombatDamageCondition();
+    private static final BeforeCombatDamageCondition instance = new BeforeCombatDamageCondition();
 
     public static Condition getInstance() {
-        return fInstance;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/a/AnimistsAwakening.java

@@ -103,7 +103,7 @@ class AnimistsAwakeningEffect extends OneShotEffect {
             controller.moveCards(toBattlefield, Zone.BATTLEFIELD, source, game, true, false, true, null);
             controller.putCardsOnBottomOfLibrary(cards, game, source, true);
 
-            if (SpellMasteryCondition.getInstance().apply(game, source)) {
+            if (SpellMasteryCondition.instance.apply(game, source)) {
                 for (Card card : toBattlefield) {
                     Permanent land = game.getPermanent(card.getId());
                     if (land != null) {

Mage.Sets/src/mage/cards/a/AnthemOfRakdos.java

@@ -28,6 +28,7 @@
 package mage.cards.a;
 
 import java.util.UUID;
+
 import mage.abilities.Ability;
 import mage.abilities.common.AttacksCreatureYouControlTriggeredAbility;
 import mage.abilities.common.SimpleStaticAbility;
@@ -46,7 +47,6 @@ import mage.game.Game;
 import mage.game.events.GameEvent;
 
 /**
- *
  * @author JotaPeRL
  */
 public class AnthemOfRakdos extends CardImpl {
@@ -101,7 +101,7 @@ class AnthemOfRakdosHellbentEffect extends ReplacementEffectImpl {
 
     @Override
     public boolean applies(GameEvent event, Ability source, Game game) {
-        return game.getControllerId(event.getSourceId()).equals(source.getControllerId()) && HellbentCondition.getInstance().apply(game, source);
+        return game.getControllerId(event.getSourceId()).equals(source.getControllerId()) && HellbentCondition.instance.apply(game, source);
     }
 
     @Override

Mage.Sets/src/mage/cards/a/AnyaMercilessAngel.java

@@ -73,7 +73,7 @@ public class AnyaMercilessAngel extends CardImpl {
         // As long as an opponent's life total is less than half his or her starting life total, Anya has indestructible.
         this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD,
                 new ConditionalContinuousEffect(new GainAbilitySourceEffect(IndestructibleAbility.getInstance(), Duration.WhileOnBattlefield),
-                        AnyaMercilessAngelCondition.getInstance(),
+                        AnyaMercilessAngelCondition.instance,
                         "As long as an opponent's life total is less than half his or her starting life total, {this} has indestructible")));
     }
 
@@ -121,16 +121,9 @@ class AnyaMercilessAngelDynamicValue implements DynamicValue {
     }
 }
 
-class AnyaMercilessAngelCondition implements Condition {
+enum AnyaMercilessAngelCondition implements Condition {
-
-    private static final AnyaMercilessAngelCondition fInstance = new AnyaMercilessAngelCondition();
-
-    public static AnyaMercilessAngelCondition getInstance() {
-        return fInstance;
-    }
-
-    private AnyaMercilessAngelCondition() {}
 
+    instance;
     @Override
     public boolean apply(Game game, Ability source) {
         return new AnyaMercilessAngelDynamicValue().calculate(game, source, null) > 0;

Mage.Sets/src/mage/cards/a/ArcTrail.java

@@ -84,14 +84,14 @@ public class ArcTrail extends CardImpl {
 
 class ArcTrailEffect extends OneShotEffect {
 
-    private static final ArcTrailEffect fINSTANCE =  new ArcTrailEffect();
+    private static final ArcTrailEffect instance =  new ArcTrailEffect();
 
     private Object readResolve() throws ObjectStreamException {
-        return fINSTANCE;
+        return instance;
     }
 
     public static ArcTrailEffect getInstance() {
-        return fINSTANCE;
+        return instance;
     }
 
     private ArcTrailEffect ( ) {
@@ -128,7 +128,7 @@ class ArcTrailEffect extends OneShotEffect {
 
     @Override
     public Effect copy() {
-        return fINSTANCE;
+        return instance;
     }
 
 }

Mage.Sets/src/mage/cards/a/ArchiveTrap.java

@@ -113,10 +113,10 @@ class ArchiveTrapWatcher extends Watcher {
 
 class OpponentSearchesLibCondition implements Condition {
 
-    private static final OpponentSearchesLibCondition fInstance = new OpponentSearchesLibCondition();
+    private static final OpponentSearchesLibCondition instance = new OpponentSearchesLibCondition();
 
     public static Condition getInstance() {
-        return fInstance;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/a/ArcticMerfolk.java

@@ -60,7 +60,7 @@ public class ArcticMerfolk extends CardImpl {
         // If Arctic Merfolk was kicked, it enters the battlefield with a +1/+1 counter on it.
         this.addAbility(new EntersBattlefieldAbility(
                 new AddCountersSourceEffect(CounterType.P1P1.createInstance()),
-                KickedCondition.getInstance(),"If Arctic Merfolk was kicked, it enters the battlefield with a +1/+1 counter on it.",""));
+                KickedCondition.instance,"If Arctic Merfolk was kicked, it enters the battlefield with a +1/+1 counter on it.",""));
     }
 
     public ArcticMerfolk(final ArcticMerfolk card) {

Mage.Sets/src/mage/cards/a/ArdentRecruit.java

@@ -57,7 +57,7 @@ public class ArdentRecruit extends CardImpl {
         this.power = new MageInt(1);
         this.toughness = new MageInt(1);
         ContinuousEffect boostSource = new BoostSourceEffect(2, 2, Duration.WhileOnBattlefield);
-        ConditionalContinuousEffect effect = new ConditionalContinuousEffect(boostSource, MetalcraftCondition.getInstance(), "Ardent Recruit gets +2/+2 as long as you control three or more artifacts");
+        ConditionalContinuousEffect effect = new ConditionalContinuousEffect(boostSource, MetalcraftCondition.instance, "Ardent Recruit gets +2/+2 as long as you control three or more artifacts");
         Ability ability = new SimpleStaticAbility(Zone.BATTLEFIELD, effect);
         ability.setAbilityWord(AbilityWord.METALCRAFT);
         this.addAbility(ability);

Mage.Sets/src/mage/cards/a/ArdentSoldier.java

@@ -59,7 +59,7 @@ public class ArdentSoldier extends CardImpl {
         this.addAbility(VigilanceAbility.getInstance());
         // If Ardent Soldier was kicked, it enters the battlefield with a +1/+1 counter on it.
         this.addAbility(new EntersBattlefieldAbility(new AddCountersSourceEffect(CounterType.P1P1.createInstance(1)),
-            KickedCondition.getInstance(), "If {this} was kicked, it enters the battlefield with a +1/+1 counter on it.", ""));
+            KickedCondition.instance, "If {this} was kicked, it enters the battlefield with a +1/+1 counter on it.", ""));
     }
 
     public ArdentSoldier(final ArdentSoldier card) {

Mage.Sets/src/mage/cards/a/ArgentSphinx.java

@@ -66,7 +66,7 @@ public class ArgentSphinx extends CardImpl {
         this.addAbility(FlyingAbility.getInstance());
 
         // Metalcraft - {U}: Exile Argent Sphinx. Return it to the battlefield under your control at the beginning of the next end step. Activate this ability only if you control three or more artifacts.
-        Ability ability = new ActivateIfConditionActivatedAbility(Zone.BATTLEFIELD, new ArgentSphinxEffect(), new ManaCostsImpl("{U}"), MetalcraftCondition.getInstance());
+        Ability ability = new ActivateIfConditionActivatedAbility(Zone.BATTLEFIELD, new ArgentSphinxEffect(), new ManaCostsImpl("{U}"), MetalcraftCondition.instance);
         ability.setAbilityWord(AbilityWord.METALCRAFT);
         this.addAbility(ability);
     }

Mage.Sets/src/mage/cards/a/ArrowStorm.java

@@ -51,13 +51,13 @@ public class ArrowStorm extends CardImpl {
         // Arrow Storm deals 4 damage to target creature or player.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new DamageTargetEffect(4),
-                new InvertCondition(RaidCondition.getInstance()),
+                new InvertCondition(RaidCondition.instance),
                 "{this} deals 4 damage to target creature or player"));
         this.getSpellAbility().addTarget(new TargetCreatureOrPlayer());
         // Raid - If you attacked with a creature this turn, instead Arrow Storm deals 5 damage to that creature or player and the damage can't be prevented.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new DamageTargetEffect(5, false),
-                RaidCondition.getInstance(),
+                RaidCondition.instance,
                 "<br/><br/><i>Raid</i> - If you attacked with a creature this turn, instead {this} deals 5 damage to that creature or player and the damage can't be prevented"));
         this.getSpellAbility().addWatcher(new PlayerAttackedWatcher());
     }

Mage.Sets/src/mage/cards/a/ArrowVolleyTrap.java

@@ -70,10 +70,10 @@ public class ArrowVolleyTrap extends CardImpl {
 
 class ArrowVolleyTrapCondition implements Condition {
 
-    private static final ArrowVolleyTrapCondition fInstance = new ArrowVolleyTrapCondition();
+    private static final ArrowVolleyTrapCondition instance = new ArrowVolleyTrapCondition();
 
     public static Condition getInstance() {
-        return fInstance;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/a/AsajjVentress.java

@@ -28,6 +28,7 @@
 package mage.cards.a;
 
 import java.util.UUID;
+
 import mage.MageInt;
 import mage.abilities.Ability;
 import mage.abilities.common.AttacksTriggeredAbility;
@@ -47,7 +48,6 @@ import mage.target.common.TargetCreaturePermanent;
 import mage.watchers.common.LifeLossOtherFromCombatWatcher;
 
 /**
- *
  * @author Styxo
  */
 public class AsajjVentress extends CardImpl {
@@ -72,7 +72,7 @@ public class AsajjVentress extends CardImpl {
         // <i>Hate</i> &mdash; Whenever Asajj Ventress attacks, if an opponent lost life from a source other than combat damage this turn, target creature blocks this turn if able.
         Ability ability = new ConditionalTriggeredAbility(
                 new AttacksTriggeredAbility(new BlocksIfAbleTargetEffect(Duration.EndOfTurn), false),
-                HateCondition.getInstance(),
+                HateCondition.instance,
                 "<i>Hate</i> &mdash; Whenever Asajj Ventress attacks, if an opponent lost life from a source other than combat damage this turn, target creature blocks this turn if able");
         ability.addTarget(new TargetCreaturePermanent());
         this.addAbility(ability, new LifeLossOtherFromCombatWatcher());

Mage.Sets/src/mage/cards/a/AshnodsBattleGear.java

@@ -28,6 +28,7 @@
 package mage.cards.a;
 
 import java.util.UUID;
+
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleActivatedAbility;
 import mage.abilities.common.SkipUntapOptionalAbility;
@@ -44,7 +45,6 @@ import mage.constants.Zone;
 import mage.target.common.TargetControlledCreaturePermanent;
 
 /**
- *
  * @author LoneFox
  */
 public class AshnodsBattleGear extends CardImpl {
@@ -56,7 +56,7 @@ public class AshnodsBattleGear extends CardImpl {
         this.addAbility(new SkipUntapOptionalAbility());
         // {2}, {tap}: Target creature you control gets +2/-2 for as long as Ashnod's Battle Gear remains tapped.
         Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(
-            new BoostTargetEffect(2, -2, Duration.Custom), SourceTappedCondition.getInstance(),
+                new BoostTargetEffect(2, -2, Duration.Custom), SourceTappedCondition.instance,
                 "target creature you control gets +2/-2 for as long as {this} remains tapped"), new ManaCostsImpl("{2}"));
         ability.addCost(new TapSourceCost());
         ability.addTarget(new TargetControlledCreaturePermanent());

Mage.Sets/src/mage/cards/a/AtarkaBeastbreaker.java

@@ -59,7 +59,7 @@ public class AtarkaBeastbreaker extends CardImpl {
                 Zone.BATTLEFIELD,
                 new BoostSourceEffect(4,4, Duration.EndOfTurn),
                 new ManaCostsImpl("{4}{G}"),
-                FormidableCondition.getInstance());
+                FormidableCondition.instance);
         ability.setAbilityWord(AbilityWord.FORMIDABLE);
         this.addAbility(ability);
     }

Mage.Sets/src/mage/cards/a/AtarkaPummeler.java

@@ -69,7 +69,7 @@ public class AtarkaPummeler extends CardImpl {
                 Zone.BATTLEFIELD,
                 new GainAbilityAllEffect(new MenaceAbility(), Duration.EndOfTurn, filter),
                 new ManaCostsImpl("{3}{R}{R}"),
-                FormidableCondition.getInstance());
+                FormidableCondition.instance);
         ability.setAbilityWord(AbilityWord.FORMIDABLE);
         this.addAbility(ability);
 

Mage.Sets/src/mage/cards/a/AuriokEdgewright.java

@@ -58,7 +58,7 @@ public class AuriokEdgewright extends CardImpl {
         this.toughness = new MageInt(2);
 
         ContinuousEffect effect = new GainAbilitySourceEffect(DoubleStrikeAbility.getInstance(), Duration.WhileOnBattlefield);
-        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect, MetalcraftCondition.getInstance(), effectText)));
+        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect, MetalcraftCondition.instance, effectText)));
     }
 
     public AuriokEdgewright(final AuriokEdgewright card) {

Mage.Sets/src/mage/cards/a/AuriokSunchaser.java

@@ -60,9 +60,9 @@ public class AuriokSunchaser extends CardImpl {
         this.toughness = new MageInt(1);
 
         ContinuousEffect effect1 = new BoostSourceEffect(2, 2, Duration.WhileOnBattlefield);
-        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect1, MetalcraftCondition.getInstance(), effect1Text)));
+        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect1, MetalcraftCondition.instance, effect1Text)));
         ContinuousEffect effect2 = new GainAbilitySourceEffect(FlyingAbility.getInstance(), Duration.WhileOnBattlefield);
-        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect2, MetalcraftCondition.getInstance(), effect2Text)));
+        this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(effect2, MetalcraftCondition.instance, effect2Text)));
     }
 
     public AuriokSunchaser(final AuriokSunchaser card) {

Mage.Sets/src/mage/cards/a/AutumnalGloom.java

@@ -59,7 +59,7 @@ public class AutumnalGloom extends CardImpl {
 
         // <i>Delirium</i> &mdash; At the beginning of your end step, if there are four or more card types among cards in your graveyard, transform Autumnal Gloom.
         this.addAbility(new TransformAbility());
-        Ability ability = new BeginningOfEndStepTriggeredAbility(Zone.BATTLEFIELD, new TransformSourceEffect(true), TargetController.YOU, DeliriumCondition.getInstance(), false);
+        Ability ability = new BeginningOfEndStepTriggeredAbility(Zone.BATTLEFIELD, new TransformSourceEffect(true), TargetController.YOU, DeliriumCondition.instance, false);
         ability.setAbilityWord(AbilityWord.DELIRIUM);
         this.addAbility(ability);
     }

Mage.Sets/src/mage/cards/b/BackwoodsSurvivalists.java

@@ -56,9 +56,9 @@ public class BackwoodsSurvivalists extends CardImpl {
         this.toughness = new MageInt(3);
 
         // <i>Delirium</i> &mdash; Backwoods Survivalists gets +1/+1 and has trample as long as there are four or more card types among cards in your graveyard.
-        ConditionalContinuousEffect effect = new ConditionalContinuousEffect(new BoostSourceEffect(1, 1, Duration.WhileOnBattlefield), DeliriumCondition.getInstance(), "<i>Delirium</i> &mdash; {this} gets +1/+1");
+        ConditionalContinuousEffect effect = new ConditionalContinuousEffect(new BoostSourceEffect(1, 1, Duration.WhileOnBattlefield), DeliriumCondition.instance, "<i>Delirium</i> &mdash; {this} gets +1/+1");
         Ability ability = new SimpleStaticAbility(Zone.BATTLEFIELD, effect);
-        ability.addEffect(new ConditionalContinuousEffect(new GainAbilitySourceEffect(TrampleAbility.getInstance()), DeliriumCondition.getInstance(), "and has trample as long as there are four or more card types among cards in your graveyard."));
+        ability.addEffect(new ConditionalContinuousEffect(new GainAbilitySourceEffect(TrampleAbility.getInstance()), DeliriumCondition.instance, "and has trample as long as there are four or more card types among cards in your graveyard."));
         this.addAbility(ability);
     }
 

Mage.Sets/src/mage/cards/b/BalothCageTrap.java

@@ -71,10 +71,10 @@ public class BalothCageTrap extends CardImpl {
 
 class BalothCageTrapCondition implements Condition {
 
-    private static final BalothCageTrapCondition fInstance = new BalothCageTrapCondition();
+    private static final BalothCageTrapCondition instance = new BalothCageTrapCondition();
 
     public static Condition getInstance() {
-        return fInstance;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/b/BaneOfHanweir.java

@@ -64,7 +64,7 @@ public class BaneOfHanweir extends CardImpl {
 
         // At the beginning of each upkeep, if a player cast two or more spells last turn, transform Bane of Hanweir.
         TriggeredAbility ability = new BeginningOfUpkeepTriggeredAbility(new TransformSourceEffect(false), TargetController.ANY, false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, TwoOrMoreSpellsWereCastLastTurnCondition.getInstance(), TransformAbility.TWO_OR_MORE_SPELLS_TRANSFORM_RULE));
+        this.addAbility(new ConditionalTriggeredAbility(ability, TwoOrMoreSpellsWereCastLastTurnCondition.instance, TransformAbility.TWO_OR_MORE_SPELLS_TRANSFORM_RULE));
     }
 
     public BaneOfHanweir(final BaneOfHanweir card) {

Mage.Sets/src/mage/cards/b/BarrageOfBoulders.java

@@ -64,7 +64,7 @@ public class BarrageOfBoulders extends CardImpl {
         Effect effect = new ConditionalRestrictionEffect(
                 Duration.EndOfTurn,
                 new CantBlockAllEffect(new FilterCreaturePermanent("creatures"), Duration.EndOfTurn),
-                new LockedInCondition(FerociousCondition.getInstance()), null);
+                new LockedInCondition(FerociousCondition.instance), null);
         effect.setText("<br/><i>Ferocious</i> &mdash; If you control a creature with power 4 or greater, creatures can't block this turn");
         this.getSpellAbility().addEffect(effect);
     }

Mage.Sets/src/mage/cards/b/BatheInBacta.java

@@ -49,7 +49,7 @@ public class BatheInBacta extends CardImpl {
         // You gain 6 life. If you lost life from a source other than combat damage this turn, you gain 9 life instead.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new GainLifeEffect(6), new GainLifeEffect(9),
-                new InvertCondition(HateCondition.getInstance()),
+                new InvertCondition(HateCondition.instance),
                 "You gain 6 life. If you lost life from a source other than combat damage this turn, you gain 9 life instead"));
         this.getSpellAbility().addWatcher(new LifeLossOtherFromCombatWatcher());
     }

Mage.Sets/src/mage/cards/b/BellowingSaddlebrute.java

@@ -56,7 +56,7 @@ public class BellowingSaddlebrute extends CardImpl {
         // Raid - When Bellowing Saddlebrute enters the battlefield, you lose 4 life unless you attacked with a creature this turn
         this.addAbility(new ConditionalTriggeredAbility(
                 new EntersBattlefieldTriggeredAbility(new LoseLifeSourceControllerEffect(4)),
-                new InvertCondition(RaidCondition.getInstance()),
+                new InvertCondition(RaidCondition.instance),
                 "<i>Raid</i> - When {this} enters the battlefield, you lose 4 life unless you attacked with a creature this turn"
         ), new PlayerAttackedWatcher());
     }

Mage.Sets/src/mage/cards/b/BenalishEmissary.java

@@ -59,7 +59,7 @@ public class BenalishEmissary extends CardImpl {
         // When Benalish Emissary enters the battlefield, if it was kicked, destroy target land.
         TriggeredAbility ability = new EntersBattlefieldTriggeredAbility(new DestroyTargetEffect());
         ability.addTarget(new TargetLandPermanent());
-        this.addAbility(new ConditionalTriggeredAbility(ability, KickedCondition.getInstance(),
+        this.addAbility(new ConditionalTriggeredAbility(ability, KickedCondition.instance,
             "When {this} enters the battlefield, if it was kicked, destroy target land."));
     }
 

Mage.Sets/src/mage/cards/b/BenalishLancer.java

@@ -60,7 +60,7 @@ public class BenalishLancer extends CardImpl {
 
         // If Benalish Lancer was kicked, it enters the battlefield with two +1/+1 counters on it and with first strike.
         Ability ability = new EntersBattlefieldAbility(new AddCountersSourceEffect(CounterType.P1P1.createInstance(2)),
-                KickedCondition.getInstance(),
+                KickedCondition.instance,
                 "If {this} was kicked, it enters the battlefield with two +1/+1 counters on it and with first strike.", "");
         ability.addEffect(new GainAbilitySourceEffect(FirstStrikeAbility.getInstance(), Duration.WhileOnBattlefield));
         this.addAbility(ability);

Mage.Sets/src/mage/cards/b/BladeTribeBerserkers.java

@@ -59,7 +59,7 @@ public class BladeTribeBerserkers extends CardImpl {
 
         TriggeredAbility ability = new EntersBattlefieldTriggeredAbility(new BoostSourceEffect(3, 3, Duration.EndOfTurn), false);
         ability.addEffect(new GainAbilitySourceEffect(HasteAbility.getInstance(), Duration.EndOfTurn));
-        this.addAbility(new ConditionalTriggeredAbility(ability, MetalcraftCondition.getInstance(), effectText));
+        this.addAbility(new ConditionalTriggeredAbility(ability, MetalcraftCondition.instance, effectText));
     }
 
     public BladeTribeBerserkers(final BladeTribeBerserkers card) {

Mage.Sets/src/mage/cards/b/BleakCovenVampires.java

@@ -62,7 +62,7 @@ public class BleakCovenVampires extends CardImpl {
         Target target = new TargetPlayer();
         ability.addTarget(target);
 
-        this.addAbility(new ConditionalTriggeredAbility(ability, MetalcraftCondition.getInstance(), effectText));
+        this.addAbility(new ConditionalTriggeredAbility(ability, MetalcraftCondition.instance, effectText));
     }
 
     public BleakCovenVampires(final BleakCovenVampires card) {

Mage.Sets/src/mage/cards/b/BloodLust.java

@@ -105,10 +105,10 @@ class TargetMatchesFilterCondition implements Condition {
 
 class TargetPermanentToughnessMinus1Value implements DynamicValue {
 
-    private static final TargetPermanentToughnessMinus1Value fINSTANCE = new TargetPermanentToughnessMinus1Value();
+    private static final TargetPermanentToughnessMinus1Value instance = new TargetPermanentToughnessMinus1Value();
 
     public static TargetPermanentToughnessMinus1Value getInstance() {
-        return fINSTANCE;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/b/BloodTribute.java

@@ -74,7 +74,7 @@ public class BloodTribute extends CardImpl {
         // If Blood Tribute was kicked, you gain life equal to the life lost this way.
         Effect effect = new ConditionalOneShotEffect(
                 new BloodTributeGainLifeEffect(),
-                KickedCondition.getInstance(),
+                KickedCondition.instance,
                 "If {this} was kicked, you gain life equal to the life lost this way");
         this.getSpellAbility().addEffect(effect);
     }

Mage.Sets/src/mage/cards/b/BloodhallPriest.java

@@ -59,7 +59,7 @@ public class BloodhallPriest extends CardImpl {
         triggeredAbility.addTarget(new TargetCreatureOrPlayer());
         this.addAbility(new ConditionalTriggeredAbility(
                 triggeredAbility,
-                HellbentCondition.getInstance(),
+                HellbentCondition.instance,
                 "Whenever {this} enters the battlefield or attacks, if you have no cards in hand, {this} deals 2 damage to target creature or player"
         ));
 

Mage.Sets/src/mage/cards/b/BloodsoakedChampion.java

@@ -63,7 +63,7 @@ public class BloodsoakedChampion extends CardImpl {
                 Zone.GRAVEYARD, 
                 new ReturnSourceFromGraveyardToBattlefieldEffect(), 
                 new ManaCostsImpl<>("{1}{B}"), 
-                RaidCondition.getInstance(), 
+                RaidCondition.instance,
                 "<i>Raid</i> - {1}{B}: Return {this} from your graveyard to the battlefield. Activate this ability only if you attacked with a creature this turn");
         this.addAbility(ability, new PlayerAttackedWatcher());
     }

Mage.Sets/src/mage/cards/b/BogDown.java

@@ -54,7 +54,7 @@ public class BogDown extends CardImpl {
         this.addAbility(new KickerAbility(new SacrificeTargetCost(new TargetControlledPermanent(2, 2, new FilterControlledLandPermanent("two lands"), true))));
         // Target player discards two cards. If Bog Down was kicked, that player discards three cards instead.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new DiscardTargetEffect(3),
-            new DiscardTargetEffect(2), KickedCondition.getInstance(),
+            new DiscardTargetEffect(2), KickedCondition.instance,
             "Target player discards two cards. If {this} was kicked, that player discards three cards instead."));
         this.getSpellAbility().addTarget(new TargetPlayer());
     }

Mage.Sets/src/mage/cards/b/BoldDefense.java

@@ -55,10 +55,10 @@ public class BoldDefense extends CardImpl {
 
         // Creatures you control get +1/+1 until end of turn. If Bold Defense was kicked, instead creatures you control get +2/+2 and gain first strike until end of turn.
         this.getSpellAbility().addEffect(new ConditionalContinuousEffect(new BoostControlledEffect(2, 2, Duration.EndOfTurn),
-                new BoostTargetEffect(1, 1, Duration.EndOfTurn), new LockedInCondition(KickedCondition.getInstance()),
+                new BoostTargetEffect(1, 1, Duration.EndOfTurn), new LockedInCondition(KickedCondition.instance),
                 "Creatures you control get +1/+1 until end of turn. If {this} was kicked, instead creatures you control get +2/+2"));
         this.getSpellAbility().addEffect(new ConditionalContinuousEffect(new GainAbilityControlledEffect(FirstStrikeAbility.getInstance(), Duration.EndOfTurn, new FilterCreaturePermanent(), false),
-                null, new LockedInCondition(KickedCondition.getInstance()),
+                null, new LockedInCondition(KickedCondition.instance),
                 "and gain first strike until end of turn"));
     }
 

Mage.Sets/src/mage/cards/b/BottomlessVault.java

@@ -65,7 +65,7 @@ public class BottomlessVault extends CardImpl {
         this.addAbility(new SkipUntapOptionalAbility());
         // At the beginning of your upkeep, if Bottomless Vault is tapped, put a storage counter on it.
         OneShotEffect addStorageCounter = new AddCountersSourceEffect(CounterType.STORAGE.createInstance());
-        Effect effect = new ConditionalOneShotEffect(addStorageCounter, SourceTappedCondition.getInstance(), "if {this} is tapped, put a storage counter on it");
+        Effect effect = new ConditionalOneShotEffect(addStorageCounter, SourceTappedCondition.instance, "if {this} is tapped, put a storage counter on it");
         this.addAbility(new BeginningOfUpkeepTriggeredAbility(Zone.BATTLEFIELD, effect, TargetController.YOU, false));
         // {tap}, Remove any number of storage counters from Bottomless Vault: Add {B} to your mana pool for each storage counter removed this way.
         Ability ability = new DynamicManaAbility(

Mage.Sets/src/mage/cards/b/BrandedHowler.java

@@ -59,7 +59,7 @@ public class BrandedHowler extends CardImpl {
 
         // At the beginning of each upkeep, if a player cast two or more spells last turn, transform Branded Howler.
         TriggeredAbility ability = new BeginningOfUpkeepTriggeredAbility(new TransformSourceEffect(false), TargetController.ANY, false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, TwoOrMoreSpellsWereCastLastTurnCondition.getInstance(), TransformAbility.TWO_OR_MORE_SPELLS_TRANSFORM_RULE));
+        this.addAbility(new ConditionalTriggeredAbility(ability, TwoOrMoreSpellsWereCastLastTurnCondition.instance, TransformAbility.TWO_OR_MORE_SPELLS_TRANSFORM_RULE));
     }
 
     public BrandedHowler(final BrandedHowler card) {

Mage.Sets/src/mage/cards/b/BreakOfDay.java

@@ -56,7 +56,7 @@ public class BreakOfDay extends CardImpl {
         // Fateful hour - If you have 5 or less life, those creatures also are indestructible this turn.
         this.getSpellAbility().addEffect(new ConditionalContinuousEffect(
                 new GainAbilityAllEffect(IndestructibleAbility.getInstance(), Duration.EndOfTurn, new FilterControlledCreaturePermanent("creatures you control"), false),
-                new LockedInCondition(FatefulHourCondition.getInstance()),
+                new LockedInCondition(FatefulHourCondition.instance),
                 "If you have 5 or less life, those creatures also are indestructible this turn"));
     }
 

Mage.Sets/src/mage/cards/b/BreakneckRider.java

@@ -61,7 +61,7 @@ public class BreakneckRider extends CardImpl {
         // At the beginning of each upkeep, if no spells were cast last turn, transform Breakneck Rider.
         this.addAbility(new TransformAbility());
         TriggeredAbility ability = new BeginningOfUpkeepTriggeredAbility(new TransformSourceEffect(true), TargetController.ANY, false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, NoSpellsWereCastLastTurnCondition.getInstance(), TransformAbility.NO_SPELLS_TRANSFORM_RULE));
+        this.addAbility(new ConditionalTriggeredAbility(ability, NoSpellsWereCastLastTurnCondition.instance, TransformAbility.NO_SPELLS_TRANSFORM_RULE));
     }
 
     public BreakneckRider(final BreakneckRider card) {

Mage.Sets/src/mage/cards/b/BreathOfDarigaaz.java

@@ -60,7 +60,7 @@ public class BreathOfDarigaaz extends CardImpl {
 
         // Breath of Darigaaz deals 1 damage to each creature without flying and each player. If Breath of Darigaaz was kicked, it deals 4 damage to each creature without flying and each player instead.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new DamageEverythingEffect(4, filter),
-                new DamageEverythingEffect(1, filter), KickedCondition.getInstance(),
+                new DamageEverythingEffect(1, filter), KickedCondition.instance,
                 "{this} deals 1 damage to each creature without flying and each player. If {this} was kicked, it deals 4 damage to each creature without flying and each player instead."));
     }
 

Mage.Sets/src/mage/cards/b/BriarbridgePatrol.java

@@ -79,10 +79,10 @@ public class BriarbridgePatrol extends CardImpl {
 
 class BriarbridgePatrolCondition implements Condition {
 
-    private static final BriarbridgePatrolCondition fInstance = new BriarbridgePatrolCondition();
+    private static final BriarbridgePatrolCondition instance = new BriarbridgePatrolCondition();
 
     public static Condition getInstance() {
-        return fInstance;
+        return instance;
     }
 
     @Override

Mage.Sets/src/mage/cards/b/BullRancor.java

@@ -59,7 +59,7 @@ public class BullRancor extends CardImpl {
         // As long as Bull Rancor is monstrous, creatures you control have menace.
         this.addAbility(new SimpleStaticAbility(Zone.BATTLEFIELD, new ConditionalContinuousEffect(
                 new GainAbilityControlledEffect(new MenaceAbility(), Duration.WhileOnBattlefield),
-                MonstrousCondition.getInstance(),
+                MonstrousCondition.instance,
                 "As long as Bull Rancor is monstrous, creatures you control have menace")
         ));
     }

Mage.Sets/src/mage/cards/b/BurstLightning.java

@@ -54,7 +54,7 @@ public class BurstLightning extends CardImpl {
         // Burst Lightning deals 2 damage to target creature or player. If Burst Lightning was kicked, it deals 4 damage to that creature or player instead.
         this.getSpellAbility().addTarget(new TargetCreatureOrPlayer());
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new DamageTargetEffect(4),
-                new DamageTargetEffect(2), KickedCondition.getInstance(), "{this} deals 2 damage to target creature or player. If {this} was kicked, it deals 4 damage to that creature or player instead"));
+                new DamageTargetEffect(2), KickedCondition.instance, "{this} deals 2 damage to target creature or player. If {this} was kicked, it deals 4 damage to that creature or player instead"));
     }
 
     public BurstLightning(final BurstLightning card) {

Mage.Sets/src/mage/cards/c/CacklingFlames.java

@@ -51,12 +51,12 @@ public class CacklingFlames extends CardImpl {
         // Cackling Flames deals 3 damage to target creature or player.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new DamageTargetEffect(3),
-                new InvertCondition(HellbentCondition.getInstance()),
+                new InvertCondition(HellbentCondition.instance),
                 "{this} deals 3 damage to target creature or player"));        
         // Hellbent - Cackling Flames deals 5 damage to that creature or player instead if you have no cards in hand.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(
                 new DamageTargetEffect(5),
-                HellbentCondition.getInstance(),
+                HellbentCondition.instance,
                 "<br/><br/><i>Hellbent</i> - {this} deals 5 damage to that creature or player instead if you have no cards in hand."));
         
         this.getSpellAbility().addTarget(new TargetCreatureOrPlayer());

Mage.Sets/src/mage/cards/c/CalculatedDismissal.java

@@ -51,7 +51,7 @@ public class CalculatedDismissal extends CardImpl {
         this.getSpellAbility().addTarget(new TargetSpell());
         this.getSpellAbility().addEffect(new CounterUnlessPaysEffect(new GenericManaCost(3)));
         // <i>Spell mastery</i> &mdash; If there are two or more instant and/or sorcery cards in your graveyard, scry 2.
-        this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new ScryEffect(2), SpellMasteryCondition.getInstance(),
+        this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new ScryEffect(2), SpellMasteryCondition.instance,
                 "<br><i>Spell mastery</i> &mdash; If there are two or more instant and/or sorcery cards in your graveyard, scry 2"));
     }
 

Mage.Sets/src/mage/cards/c/CallForUnity.java

@@ -60,7 +60,7 @@ public class CallForUnity extends CardImpl {
 
         // <i>Revolt</i> &mdash; At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a unity counter on Call for Unity.
         TriggeredAbility ability = new BeginningOfYourEndStepTriggeredAbility(new AddCountersSourceEffect(CounterType.UNITY.createInstance(), true), false);
-        this.addAbility(new ConditionalTriggeredAbility(ability, RevoltCondition.getInstance(), ruleText), new RevoltWatcher());
+        this.addAbility(new ConditionalTriggeredAbility(ability, RevoltCondition.instance, ruleText), new RevoltWatcher());
 
         // Creatures you control get +1/+1 for each unity counter on Call for Unity.
         Effect effect = new BoostControlledEffect(new CountersSourceCount(CounterType.UNITY), new CountersSourceCount(CounterType.UNITY), Duration.WhileOnBattlefield,

Mage.Sets/src/mage/cards/c/CallOfTheFullMoon.java

@@ -78,7 +78,7 @@ public class CallOfTheFullMoon extends CardImpl {
 
         // At the beginning of each upkeep, if a player cast two or more spells last turn, sacrifice Call of the Full Moon.
         TriggeredAbility ability2 = new BeginningOfUpkeepTriggeredAbility(new SacrificeSourceEffect(), TargetController.ANY, false);
-        this.addAbility(new ConditionalTriggeredAbility(ability2, TwoOrMoreSpellsWereCastLastTurnCondition.getInstance(),
+        this.addAbility(new ConditionalTriggeredAbility(ability2, TwoOrMoreSpellsWereCastLastTurnCondition.instance,
             "At the beginning of each upkeep, if a player cast two or more spells last turn, sacrifice {this}."));
     }
 

Mage.Sets/src/mage/cards/c/CanopySurge.java

@@ -58,7 +58,7 @@ public class CanopySurge extends CardImpl {
         this.addAbility(new KickerAbility("{2}"));
         // Canopy Surge deals 1 damage to each creature with flying and each player. If Canopy Surge was kicked, it deals 4 damage to each creature with flying and each player instead.
         this.getSpellAbility().addEffect(new ConditionalOneShotEffect(new DamageEverythingEffect(4, filter),
-            new DamageEverythingEffect(1, filter), KickedCondition.getInstance(),
+            new DamageEverythingEffect(1, filter), KickedCondition.instance,
             "{this} deals 1 damage to each creature with flying and each player. If {this} was kicked, it deals 4 damage to each creature with flying and each player instead."));
     }