#421 Create PluginHooks

- PluginHooks manages third-party plugins and allows to perform actions and queries on them, instead of public fields on the AuthMe main class

src/main/java/fr/xephi/authme/AuthMe.java

@@ -1,9 +1,8 @@
 package fr.xephi.authme;
 
-import com.earth2me.essentials.Essentials;
-import com.onarandombox.MultiverseCore.MultiverseCore;
 import fr.xephi.authme.api.API;
 import fr.xephi.authme.api.NewAPI;
+import fr.xephi.authme.cache.IpAddressManager;
 import fr.xephi.authme.cache.auth.PlayerAuth;
 import fr.xephi.authme.cache.auth.PlayerCache;
 import fr.xephi.authme.cache.backup.JsonCache;
@@ -23,6 +22,7 @@ import fr.xephi.authme.datasource.MySQL;
 import fr.xephi.authme.datasource.SQLite;
 import fr.xephi.authme.hooks.BungeeCordMessage;
 import fr.xephi.authme.hooks.EssSpawn;
+import fr.xephi.authme.hooks.PluginHooks;
 import fr.xephi.authme.listener.AuthMeBlockListener;
 import fr.xephi.authme.listener.AuthMeEntityListener;
 import fr.xephi.authme.listener.AuthMeInventoryPacketAdapter;
@@ -33,7 +33,6 @@ import fr.xephi.authme.listener.AuthMeServerListener;
 import fr.xephi.authme.listener.AuthMeTabCompletePacketAdapter;
 import fr.xephi.authme.listener.AuthMeTablistPacketAdapter;
 import fr.xephi.authme.mail.SendMailSSL;
-import fr.xephi.authme.cache.IpAddressManager;
 import fr.xephi.authme.output.ConsoleFilter;
 import fr.xephi.authme.output.Log4JFilter;
 import fr.xephi.authme.output.MessageKey;
@@ -60,7 +59,6 @@ import fr.xephi.authme.util.GeoLiteAPI;
 import fr.xephi.authme.util.MigrationService;
 import fr.xephi.authme.util.StringUtils;
 import fr.xephi.authme.util.Utils;
-import net.minelink.ctplus.CombatTagPlus;
 import org.apache.logging.log4j.LogManager;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
@@ -123,21 +121,19 @@ public class AuthMe extends JavaPlugin {
      * Plugin Hooks
      * TODO: Move into modules
      */
-    public Essentials ess;
-    public MultiverseCore multiverse;
-    public CombatTagPlus combatTagPlus;
     public AuthMeInventoryPacketAdapter inventoryProtector;
     public AuthMeTabCompletePacketAdapter tabComplete;
     public AuthMeTablistPacketAdapter tablistHider;
     private Management management;
-    private CommandHandler commandHandler = null;
+    private CommandHandler commandHandler;
-    private PermissionsManager permsMan = null;
+    private PermissionsManager permsMan;
     private NewSetting newSettings;
     private Messages messages;
     private JsonCache playerBackup;
     private PasswordSecurity passwordSecurity;
     private DataSource database;
     private IpAddressManager ipAddressManager;
+    private PluginHooks pluginHooks;
 
     /**
      * Get the plugin's instance.
@@ -247,13 +243,16 @@ public class AuthMe extends JavaPlugin {
             return;
         }
 
+        pluginHooks = new PluginHooks(server.getPluginManager());
+
         MigrationService.changePlainTextToSha256(newSettings, database, new SHA256());
         passwordSecurity = new PasswordSecurity(getDataSource(), newSettings, Bukkit.getPluginManager());
         ipAddressManager = new IpAddressManager(newSettings);
 
         // Set up the permissions manager and command handler
         permsMan = initializePermissionsManager();
-        commandHandler = initializeCommandHandler(permsMan, messages, passwordSecurity, newSettings, ipAddressManager);
+        commandHandler = initializeCommandHandler(permsMan, messages, passwordSecurity, newSettings, ipAddressManager,
+            pluginHooks);
 
         // Set up Metrics
         MetricsStarter.setupMetrics(plugin, newSettings);
@@ -271,14 +270,8 @@ public class AuthMe extends JavaPlugin {
         setupMailApi();
 
         // Hooks
-        // Check Combat Tag Plus Version
-        checkCombatTagPlus();
-
-        // Check Multiverse
-        checkMultiverse();
-
         // Check Essentials
-        checkEssentials();
+        checkEssentialsSpawn();
 
         // Check if the ProtocolLib is available. If so we could listen for
         // inventory protection
@@ -293,14 +286,14 @@ public class AuthMe extends JavaPlugin {
         playerBackup = new JsonCache();
 
         // Set the DataManager
-        dataManager = new DataManager(this);
+        dataManager = new DataManager(this, pluginHooks);
 
         // Set up the new API
         setupApi();
 
         // Set up the management
         ProcessService processService = new ProcessService(newSettings, messages, this, ipAddressManager,
-            passwordSecurity);
+            passwordSecurity, pluginHooks);
         management = new Management(this, processService, database, PlayerCache.getInstance());
 
         // Set up the BungeeCord hook
@@ -384,7 +377,7 @@ public class AuthMe extends JavaPlugin {
         pluginManager.registerEvents(new AuthMePlayerListener(this), this);
         pluginManager.registerEvents(new AuthMeBlockListener(), this);
         pluginManager.registerEvents(new AuthMeEntityListener(), this);
-        pluginManager.registerEvents(new AuthMeServerListener(this), this);
+        pluginManager.registerEvents(new AuthMeServerListener(this, messages, pluginHooks), this);
 
         // Try to register 1.6 player listeners
         try {
@@ -432,12 +425,12 @@ public class AuthMe extends JavaPlugin {
 
     private CommandHandler initializeCommandHandler(PermissionsManager permissionsManager, Messages messages,
                                                     PasswordSecurity passwordSecurity, NewSetting settings,
-                                                    IpAddressManager ipAddressManager) {
+                                                    IpAddressManager ipAddressManager, PluginHooks pluginHooks) {
         HelpProvider helpProvider = new HelpProvider(permissionsManager, settings.getProperty(HELP_HEADER));
         Set<CommandDescription> baseCommands = CommandInitializer.buildCommands();
         CommandMapper mapper = new CommandMapper(baseCommands, permissionsManager);
-        CommandService commandService = new CommandService(
+        CommandService commandService = new CommandService(this, mapper, helpProvider, messages, passwordSecurity,
-            this, mapper, helpProvider, messages, passwordSecurity, permissionsManager, settings, ipAddressManager);
+            permissionsManager, settings, ipAddressManager, pluginHooks);
         return new CommandHandler(commandService);
     }
 
@@ -640,32 +633,8 @@ public class AuthMe extends JavaPlugin {
         });
     }
 
-    // Get the Multiverse plugin
-    public void checkMultiverse() {
-        if (Settings.multiverse && server.getPluginManager().isPluginEnabled("Multiverse-Core")) {
-            try {
-                multiverse = (MultiverseCore) server.getPluginManager().getPlugin("Multiverse-Core");
-                ConsoleLogger.info("Hooked correctly with Multiverse-Core");
-            } catch (Exception | NoClassDefFoundError ignored) {
-                multiverse = null;
-            }
-        } else {
-            multiverse = null;
-        }
-    }
-
     // Get the Essentials plugin
-    public void checkEssentials() {
+    public void checkEssentialsSpawn() {
-        if (server.getPluginManager().isPluginEnabled("Essentials")) {
-            try {
-                ess = (Essentials) server.getPluginManager().getPlugin("Essentials");
-                ConsoleLogger.info("Hooked correctly with Essentials");
-            } catch (Exception | NoClassDefFoundError ignored) {
-                ess = null;
-            }
-        } else {
-            ess = null;
-        }
         if (server.getPluginManager().isPluginEnabled("EssentialsSpawn")) {
             try {
                 essentialsSpawn = new EssSpawn().getLocation();
@@ -679,20 +648,6 @@ public class AuthMe extends JavaPlugin {
         }
     }
 
-    // Check the presence of CombatTag
-    public void checkCombatTagPlus() {
-        if (server.getPluginManager().isPluginEnabled("CombatTagPlus")) {
-            try {
-                combatTagPlus = (CombatTagPlus) server.getPluginManager().getPlugin("CombatTagPlus");
-                ConsoleLogger.info("Hooked correctly with CombatTagPlus");
-            } catch (Exception | NoClassDefFoundError ignored) {
-                combatTagPlus = null;
-            }
-        } else {
-            combatTagPlus = null;
-        }
-    }
-
     // Check the presence of the ProtocolLib plugin
     public void checkProtocolLib() {
         if (!server.getPluginManager().isPluginEnabled("ProtocolLib")) {
@@ -778,7 +733,7 @@ public class AuthMe extends JavaPlugin {
             return;
         }
         ConsoleLogger.info("AutoPurging the Database: " + cleared.size() + " accounts removed!");
-        if (newSettings.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES) && this.ess != null)
+        if (newSettings.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES) && pluginHooks.isEssentialsAvailable())
             dataManager.purgeEssentials(cleared);
         if (newSettings.getProperty(PurgeSettings.REMOVE_PLAYER_DAT))
             dataManager.purgeDat(cleared);
@@ -884,4 +839,8 @@ public class AuthMe extends JavaPlugin {
         return passwordSecurity;
     }
 
+    public PluginHooks getPluginHooks() {
+        return pluginHooks;
+    }
+
 }

src/main/java/fr/xephi/authme/DataManager.java

@@ -1,5 +1,13 @@
 package fr.xephi.authme;
 
+import fr.xephi.authme.hooks.PluginHooks;
+import fr.xephi.authme.permission.PermissionsManager;
+import fr.xephi.authme.settings.Settings;
+import fr.xephi.authme.util.Utils;
+import org.bukkit.Bukkit;
+import org.bukkit.OfflinePlayer;
+import org.bukkit.entity.Player;
+
 import java.io.File;
 import java.util.List;
 import java.util.concurrent.Callable;
@@ -7,27 +15,21 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 
-import org.bukkit.Bukkit;
-import org.bukkit.OfflinePlayer;
-import org.bukkit.entity.Player;
-
-import fr.xephi.authme.permission.PermissionsManager;
-import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.util.Utils;
-
 /**
  */
 public class DataManager {
 
-    public final AuthMe plugin;
+    private final AuthMe plugin;
+    private final PluginHooks pluginHooks;
 
     /**
      * Constructor for DataManager.
      *
      * @param plugin AuthMe
      */
-    public DataManager(AuthMe plugin) {
+    public DataManager(AuthMe plugin, PluginHooks pluginHooks) {
         this.plugin = plugin;
+        this.pluginHooks = pluginHooks;
     }
 
     /**
@@ -37,7 +39,7 @@ public class DataManager {
      *
      * @return OfflinePlayer
      */
-    public synchronized OfflinePlayer getOfflinePlayer(final String name) {
+    private synchronized OfflinePlayer getOfflinePlayer(final String name) {
         ExecutorService executor = Executors.newSingleThreadExecutor();
         Future<OfflinePlayer> result = executor.submit(new Callable<OfflinePlayer>() {
 
@@ -57,7 +59,7 @@ public class DataManager {
         try {
             return result.get();
         } catch (Exception e) {
-            return (null);
+            return null;
         } finally {
             executor.shutdown();
         }
@@ -78,14 +80,13 @@ public class DataManager {
                 String playerName = player.getName();
                 File playerFile = new File("." + File.separator + "plugins" + File.separator + "AntiXRayData" + File.separator + "PlayerData" + File.separator + playerName);
                 if (playerFile.exists()) {
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 }
             } catch (Exception ignored) {
             }
         }
-        ConsoleLogger.info("AutoPurgeDatabase : Remove " + i + " AntiXRayData Files");
+        ConsoleLogger.info("AutoPurgeDatabase: Removed " + i + " AntiXRayData Files");
     }
 
     /**
@@ -103,26 +104,23 @@ public class DataManager {
                 String playerName = player.getName();
                 File playerFile = new File("." + File.separator + "plugins" + File.separator + "LimitedCreative" + File.separator + "inventories" + File.separator + playerName + ".yml");
                 if (playerFile.exists()) {
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 }
                 playerFile = new File("." + File.separator + "plugins" + File.separator + "LimitedCreative" + File.separator + "inventories" + File.separator + playerName + "_creative.yml");
                 if (playerFile.exists()) {
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 }
                 playerFile = new File("." + File.separator + "plugins" + File.separator + "LimitedCreative" + File.separator + "inventories" + File.separator + playerName + "_adventure.yml");
                 if (playerFile.exists()) {
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 }
             } catch (Exception ignored) {
             }
         }
-        ConsoleLogger.info("AutoPurgeDatabase : Remove " + i + " LimitedCreative Survival, Creative and Adventure files");
+        ConsoleLogger.info("AutoPurgeDatabase: Removed " + i + " LimitedCreative Survival, Creative and Adventure files");
     }
 
     /**
@@ -141,13 +139,11 @@ public class DataManager {
 
                 try {
                     File playerFile = new File(plugin.getServer().getWorldContainer() + File.separator + Settings.defaultWorld + File.separator + "players" + File.separator + player.getUniqueId() + ".dat");
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 } catch (Exception ignore) {
                     File playerFile = new File(plugin.getServer().getWorldContainer() + File.separator + Settings.defaultWorld + File.separator + "players" + File.separator + player.getName() + ".dat");
                     if (playerFile.exists()) {
-                        //noinspection ResultOfMethodCallIgnored
                         playerFile.delete();
                         i++;
                     }
@@ -155,7 +151,7 @@ public class DataManager {
             } catch (Exception ignore) {
             }
         }
-        ConsoleLogger.info("AutoPurgeDatabase : Remove " + i + " .dat Files");
+        ConsoleLogger.info("AutoPurgeDatabase: Removed " + i + " .dat Files");
     }
 
     /**
@@ -163,25 +159,24 @@ public class DataManager {
      *
      * @param cleared List of String
      */
-    @SuppressWarnings("deprecation")
     public void purgeEssentials(List<String> cleared) {
         int i = 0;
+        // FIXME: essentials data folder may be null
+        final File userDataFolder = new File(pluginHooks.getEssentialsDataFolder(), "userdata");
         for (String name : cleared) {
             try {
-                File playerFile = new File(plugin.ess.getDataFolder() + File.separator + "userdata" + File.separator + plugin.getServer().getOfflinePlayer(name).getUniqueId() + ".yml");
+                File playerFile = new File(userDataFolder, plugin.getServer().getOfflinePlayer(name).getUniqueId() + ".yml");
-                //noinspection ResultOfMethodCallIgnored
                 playerFile.delete();
                 i++;
             } catch (Exception e) {
-                File playerFile = new File(plugin.ess.getDataFolder() + File.separator + "userdata" + File.separator + name + ".yml");
+                File playerFile = new File(userDataFolder, name + ".yml");
                 if (playerFile.exists()) {
-                    //noinspection ResultOfMethodCallIgnored
                     playerFile.delete();
                     i++;
                 }
             }
         }
-        ConsoleLogger.info("AutoPurgeDatabase : Remove " + i + " EssentialsFiles");
+        ConsoleLogger.info("AutoPurgeDatabase: Removed " + i + " EssentialsFiles");
     }
 
     // TODO: What is this method for? Is it correct?
@@ -192,9 +187,10 @@ public class DataManager {
     public synchronized void purgePermissions(List<String> cleared) {
         // Get the permissions manager, and make sure it's valid
         PermissionsManager permsMan = this.plugin.getPermissionsManager();
-        if (permsMan == null)
+        if (permsMan == null) {
             ConsoleLogger.showError("Unable to access permissions manager instance!");
-        assert permsMan != null;
+            return;
+        }
 
         int i = 0;
         for (String name : cleared) {
@@ -204,7 +200,7 @@ public class DataManager {
             } catch (Exception ignored) {
             }
         }
-        ConsoleLogger.info("AutoPurgeDatabase : Removed " + i + "permissions");
+        ConsoleLogger.info("AutoPurgeDatabase: Removed " + i + "permissions");
 
         /*int i = 0;
         for (String name : cleared) {
@@ -220,38 +216,6 @@ public class DataManager {
         ConsoleLogger.info("AutoPurgeDatabase : Remove " + i + " Permissions");*/
     }
 
-    /**
-     * Method isOnline.
-     *
-     * @param player Player
-     * @param name   String
-     *
-     * @return boolean
-     */
-    public boolean isOnline(Player player, final String name) {
-        if (player.isOnline())
-            return true;
-        ExecutorService executor = Executors.newSingleThreadExecutor();
-        Future<Boolean> result = executor.submit(new Callable<Boolean>() {
-
-            @Override
-            public synchronized Boolean call() throws Exception {
-                for (OfflinePlayer op : Utils.getOnlinePlayers())
-                    if (op.getName().equalsIgnoreCase(name)) {
-                        return true;
-                    }
-                return false;
-            }
-        });
-        try {
-            return result.get();
-        } catch (Exception e) {
-            return false;
-        } finally {
-            executor.shutdown();
-        }
-    }
-
     /**
      * Method getOnlinePlayerLower.
      *
@@ -259,11 +223,12 @@ public class DataManager {
      *
      * @return Player
      */
-    public Player getOnlinePlayerLower(String name) {
+    private Player getOnlinePlayerLower(String name) {
         name = name.toLowerCase();
         for (Player player : Utils.getOnlinePlayers()) {
-            if (player.getName().equalsIgnoreCase(name))
+            if (player.getName().equalsIgnoreCase(name)) {
                 return player;
+            }
         }
         return null;
     }

src/main/java/fr/xephi/authme/command/CommandService.java

@@ -5,6 +5,7 @@ import fr.xephi.authme.cache.auth.PlayerCache;
 import fr.xephi.authme.command.help.HelpProvider;
 import fr.xephi.authme.datasource.DataSource;
 import fr.xephi.authme.cache.IpAddressManager;
+import fr.xephi.authme.hooks.PluginHooks;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
 import fr.xephi.authme.permission.PermissionsManager;
@@ -30,6 +31,7 @@ public class CommandService {
     private final PermissionsManager permissionsManager;
     private final NewSetting settings;
     private final IpAddressManager ipAddressManager;
+    private final PluginHooks pluginHooks;
 
     /**
      * Constructor.
@@ -45,7 +47,7 @@ public class CommandService {
      */
     public CommandService(AuthMe authMe, CommandMapper commandMapper, HelpProvider helpProvider, Messages messages,
                           PasswordSecurity passwordSecurity, PermissionsManager permissionsManager, NewSetting settings,
-                          IpAddressManager ipAddressManager) {
+                          IpAddressManager ipAddressManager, PluginHooks pluginHooks) {
         this.authMe = authMe;
         this.messages = messages;
         this.helpProvider = helpProvider;
@@ -54,6 +56,7 @@ public class CommandService {
         this.permissionsManager = permissionsManager;
         this.settings = settings;
         this.ipAddressManager = ipAddressManager;
+        this.pluginHooks = pluginHooks;
     }
 
     /**
@@ -195,4 +198,8 @@ public class CommandService {
         return PlayerCache.getInstance();
     }
 
+    public PluginHooks getPluginHooks() {
+        return pluginHooks;
+    }
+
 }

src/main/java/fr/xephi/authme/command/executable/authme/PurgeBannedPlayersCommand.java

@@ -25,7 +25,8 @@ public class PurgeBannedPlayersCommand implements ExecutableCommand {
 
         // Purge the banned players
         plugin.getDataSource().purgeBanned(bannedPlayers);
-        if (commandService.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES) && plugin.ess != null)
+        if (commandService.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES)
+            && commandService.getPluginHooks().isEssentialsAvailable())
             plugin.dataManager.purgeEssentials(bannedPlayers);
         if (commandService.getProperty(PurgeSettings.REMOVE_PLAYER_DAT))
             plugin.dataManager.purgeDat(bannedPlayers);

src/main/java/fr/xephi/authme/command/executable/authme/PurgeCommand.java

@@ -47,7 +47,8 @@ public class PurgeCommand implements ExecutableCommand {
         sender.sendMessage(ChatColor.GOLD + "Deleted " + purged.size() + " user accounts");
 
         // Purge other data
-        if (commandService.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES) && plugin.ess != null)
+        if (commandService.getProperty(PurgeSettings.REMOVE_ESSENTIALS_FILES) &&
+            commandService.getPluginHooks().isEssentialsAvailable())
             plugin.dataManager.purgeEssentials(purged);
         if (commandService.getProperty(PurgeSettings.REMOVE_PLAYER_DAT))
             plugin.dataManager.purgeDat(purged);

src/main/java/fr/xephi/authme/hooks/PluginHooks.java

@@ -0,0 +1,158 @@
+package fr.xephi.authme.hooks;
+
+import com.earth2me.essentials.Essentials;
+import com.onarandombox.MultiverseCore.MultiverseCore;
+import com.onarandombox.MultiverseCore.api.MVWorldManager;
+import fr.xephi.authme.ConsoleLogger;
+import net.minelink.ctplus.CombatTagPlus;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.plugin.PluginManager;
+
+import java.io.File;
+
+/**
+ * Hooks into third-party plugins and allows to perform actions on them.
+ */
+public class PluginHooks {
+
+    private final PluginManager pluginManager;
+    private Essentials essentials;
+    private MultiverseCore multiverse;
+    private CombatTagPlus combatTagPlus;
+
+    /**
+     * Constructor.
+     *
+     * @param pluginManager The server's plugin manager
+     */
+    public PluginHooks(PluginManager pluginManager) {
+        this.pluginManager = pluginManager;
+        tryHookToCombatPlus();
+        tryHookToEssentials();
+        tryHookToMultiverse();
+    }
+
+    /**
+     * Enable or disable the social spy status of the given user if Essentials is available.
+     *
+     * @param player The player to modify
+     * @param socialSpyStatus The social spy status (enabled/disabled) to set
+     */
+    public void setEssentialsSocialSpyStatus(Player player, boolean socialSpyStatus) {
+        if (essentials != null) {
+            essentials.getUser(player).setSocialSpyEnabled(socialSpyStatus);
+        }
+    }
+
+    /**
+     * If Essentials is hooked into, return Essentials' data folder.
+     *
+     * @return The Essentials data folder, or null if unavailable
+     */
+    public File getEssentialsDataFolder() {
+        if (essentials != null) {
+            return essentials.getDataFolder();
+        }
+        return null;
+    }
+
+    /**
+     * Return the spawn of the given world as defined by Multiverse (if available).
+     *
+     * @param world The world to get the Multiverse spawn for
+     * @return The spawn location from Multiverse, or null if unavailable
+     */
+    public Location getMultiverseSpawn(World world) {
+        if (multiverse != null) {
+            MVWorldManager manager = multiverse.getMVWorldManager();
+            if (manager.isMVWorld(world)) {
+                return manager.getMVWorld(world).getSpawnLocation();
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Query the CombatTagPlus plugin whether the given player is an NPC.
+     *
+     * @param player The player to verify
+     * @return True if the player is an NPC according to CombatTagPlus, false if not or if the plugin is unavailable
+     */
+    public boolean isNpcInCombatTagPlus(Player player) {
+        return combatTagPlus != null && combatTagPlus.getNpcPlayerHelper().isNpc(player);
+    }
+
+
+    // ------
+    // "Is plugin available" methods
+    // ------
+    public boolean isEssentialsAvailable() {
+        return essentials != null;
+    }
+
+    public boolean isMultiverseAvailable() {
+        return multiverse != null;
+    }
+
+    public boolean isCombatTagPlusAvailable() {
+        return combatTagPlus != null;
+    }
+
+    // ------
+    // Hook methods
+    // ------
+    public void tryHookToEssentials() {
+        try {
+            essentials = getPlugin(pluginManager, "Essentials", Essentials.class);
+        } catch (Exception | NoClassDefFoundError ignored) {
+            essentials = null;
+        }
+    }
+
+    public void tryHookToCombatPlus() {
+        try {
+            combatTagPlus = getPlugin(pluginManager, "CombatTagPlus", CombatTagPlus.class);
+        } catch (Exception | NoClassDefFoundError ignored) {
+            combatTagPlus = null;
+        }
+    }
+
+    public void tryHookToMultiverse() {
+        try {
+            multiverse = getPlugin(pluginManager, "Multiverse-Core", MultiverseCore.class);
+        } catch (Exception | NoClassDefFoundError ignored) {
+            multiverse = null;
+        }
+    }
+
+    // ------
+    // Unhook methods
+    // ------
+    public void unhookEssentials() {
+        essentials = null;
+    }
+    public void unhookCombatPlus() {
+        combatTagPlus = null;
+    }
+    public void unhookMultiverse() {
+        multiverse = null;
+    }
+
+    // ------
+    // Helpers
+    // ------
+    private static <T extends Plugin> T getPlugin(PluginManager pluginManager, String name, Class<T> clazz)
+        throws Exception, NoClassDefFoundError {
+        if (pluginManager.isPluginEnabled(name)) {
+            T plugin = clazz.cast(pluginManager.getPlugin(name));
+            ConsoleLogger.info("Hooked successfully into " + name);
+            return plugin;
+        }
+        return null;
+    }
+
+
+}

src/main/java/fr/xephi/authme/listener/AuthMeServerListener.java

@@ -2,6 +2,7 @@ package fr.xephi.authme.listener;
 
 import fr.xephi.authme.AuthMe;
 import fr.xephi.authme.ConsoleLogger;
+import fr.xephi.authme.hooks.PluginHooks;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
 import fr.xephi.authme.settings.Settings;
@@ -12,18 +13,19 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.server.PluginDisableEvent;
 import org.bukkit.event.server.PluginEnableEvent;
 import org.bukkit.event.server.ServerListPingEvent;
-import org.bukkit.plugin.Plugin;
 
 /**
  */
 public class AuthMeServerListener implements Listener {
 
     private final AuthMe plugin;
-    private final Messages m;
+    private final Messages messages;
+    private final PluginHooks pluginHooks;
 
-    public AuthMeServerListener(AuthMe plugin) {
+    public AuthMeServerListener(AuthMe plugin, Messages messages, PluginHooks pluginHooks) {
-        this.m = plugin.getMessages();
         this.plugin = plugin;
+        this.messages = messages;
+        this.pluginHooks = pluginHooks;
     }
 
     @EventHandler(priority = EventPriority.HIGHEST)
@@ -31,11 +33,11 @@ public class AuthMeServerListener implements Listener {
         if (!Settings.countriesBlacklist.isEmpty() || !Settings.countries.isEmpty()){
             String countryCode = GeoLiteAPI.getCountryCode(event.getAddress().getHostAddress());
             if( Settings.countriesBlacklist.contains(countryCode)) {
-                event.setMotd(m.retrieveSingle(MessageKey.COUNTRY_BANNED_ERROR));
+                event.setMotd(messages.retrieveSingle(MessageKey.COUNTRY_BANNED_ERROR));
                 return;
             }
             if (Settings.enableProtection && !Settings.countries.contains(countryCode)) {
-                event.setMotd(m.retrieveSingle(MessageKey.COUNTRY_BANNED_ERROR));
+                event.setMotd(messages.retrieveSingle(MessageKey.COUNTRY_BANNED_ERROR));
             }
         }
     }
@@ -47,35 +49,21 @@ public class AuthMeServerListener implements Listener {
             return;
         }
 
-        // Get the plugin instance
+        final String pluginName = event.getPlugin().getName();
-        Plugin pluginInstance = event.getPlugin();
+        if ("Essentials".equalsIgnoreCase(pluginName)) {
-
+            pluginHooks.unhookEssentials();
-        // Make sure it's not this plugin itself
+            ConsoleLogger.info("Essentials has been disabled: unhooking");
-        if (pluginInstance.equals(this.plugin)) {
+        } else if ("Multiverse-Core".equalsIgnoreCase(pluginName)) {
-            return;
+            pluginHooks.unhookMultiverse();
-        }
+            ConsoleLogger.info("Multiverse-Core has been disabled: unhooking");
-
+        } else if ("CombatTagPlus".equalsIgnoreCase(pluginName)) {
-        String pluginName = pluginInstance.getName();
+            pluginHooks.unhookCombatPlus();
-        if (pluginName.equalsIgnoreCase("Essentials")) {
+            ConsoleLogger.info("CombatTagPlus has been disabled: unhooking");
-            plugin.ess = null;
+        } else if ("EssentialsSpawn".equalsIgnoreCase(pluginName)) {
-            ConsoleLogger.info("Essentials has been disabled, unhook!");
-            return;
-        }
-        if (pluginName.equalsIgnoreCase("EssentialsSpawn")) {
             plugin.essentialsSpawn = null;
-            ConsoleLogger.info("EssentialsSpawn has been disabled, unhook!");
+            ConsoleLogger.info("EssentialsSpawn has been disabled: unhooking");
-            return;
-        }
-        if (pluginName.equalsIgnoreCase("Multiverse-Core")) {
-            plugin.multiverse = null;
-            ConsoleLogger.info("Multiverse-Core has been disabled, unhook!");
-            return;
-        }
-        if (pluginName.equalsIgnoreCase("CombatTagPlus")) {
-            plugin.combatTagPlus = null;
-            ConsoleLogger.info("CombatTagPlus has been disabled, unhook!");
-            return;
         }
+
         if (pluginName.equalsIgnoreCase("ProtocolLib")) {
             plugin.inventoryProtector = null;
             plugin.tablistHider = null;
@@ -86,19 +74,22 @@ public class AuthMeServerListener implements Listener {
 
     @EventHandler(priority = EventPriority.HIGHEST)
     public void onPluginEnable(PluginEnableEvent event) {
-        String pluginName = event.getPlugin().getName();
+        // Make sure the plugin instance isn't null
-        if (pluginName.equalsIgnoreCase("Essentials") || pluginName.equalsIgnoreCase("EssentialsSpawn")) {
+        if (event.getPlugin() == null) {
-            plugin.checkEssentials();
             return;
         }
-        if (pluginName.equalsIgnoreCase("Multiverse-Core")) {
+
-            plugin.checkMultiverse();
+        final String pluginName = event.getPlugin().getName();
-            return;
+        if ("Essentials".equalsIgnoreCase(pluginName)) {
-        }
+            pluginHooks.tryHookToEssentials();
-        if (pluginName.equalsIgnoreCase("CombatTagPlus")) {
+        } else if ("Multiverse-Core".equalsIgnoreCase(pluginName)) {
-            plugin.checkCombatTagPlus();
+            pluginHooks.tryHookToMultiverse();
-            return;
+        } else if ("CombatTagPlus".equalsIgnoreCase(pluginName)) {
+            pluginHooks.tryHookToCombatPlus();
+        } else if ("EssentialsSpawn".equalsIgnoreCase(pluginName)) {
+            plugin.checkEssentialsSpawn();
         }
+
         if (pluginName.equalsIgnoreCase("ProtocolLib")) {
             plugin.checkProtocolLib();
         }

src/main/java/fr/xephi/authme/process/ProcessService.java

@@ -2,6 +2,7 @@ package fr.xephi.authme.process;
 
 import fr.xephi.authme.AuthMe;
 import fr.xephi.authme.cache.IpAddressManager;
+import fr.xephi.authme.hooks.PluginHooks;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
 import fr.xephi.authme.security.PasswordSecurity;
@@ -22,14 +23,16 @@ public class ProcessService {
     private final AuthMe authMe;
     private final IpAddressManager ipAddressManager;
     private final PasswordSecurity passwordSecurity;
+    private final PluginHooks pluginHooks;
 
     public ProcessService(NewSetting settings, Messages messages, AuthMe authMe, IpAddressManager ipAddressManager,
-                          PasswordSecurity passwordSecurity) {
+                          PasswordSecurity passwordSecurity, PluginHooks pluginHooks) {
         this.settings = settings;
         this.messages = messages;
         this.authMe = authMe;
         this.ipAddressManager = ipAddressManager;
         this.passwordSecurity = passwordSecurity;
+        this.pluginHooks = pluginHooks;
     }
 
     public <T> T getProperty(Property<T> property) {
@@ -84,4 +87,8 @@ public class ProcessService {
         return passwordSecurity.computeHash(password, username);
     }
 
+    public PluginHooks getPluginHooks() {
+        return pluginHooks;
+    }
+
 }

src/main/java/fr/xephi/authme/process/join/AsynchronousJoin.java

@@ -59,8 +59,8 @@ public class AsynchronousJoin implements Process {
             return;
         }
 
-        if (plugin.ess != null && service.getProperty(HooksSettings.DISABLE_SOCIAL_SPY)) {
+        if (service.getProperty(HooksSettings.DISABLE_SOCIAL_SPY)) {
-            plugin.ess.getUser(player).setSocialSpyEnabled(false);
+            service.getPluginHooks().setEssentialsSocialSpyStatus(player, false);
         }
 
         final String ip = service.getIpAddressManager().getPlayerIp(player);

src/main/java/fr/xephi/authme/settings/Spawn.java

@@ -1,6 +1,5 @@
 package fr.xephi.authme.settings;
 
-import com.onarandombox.MultiverseCore.api.MVWorldManager;
 import fr.xephi.authme.AuthMe;
 import fr.xephi.authme.cache.auth.PlayerCache;
 import fr.xephi.authme.util.StringUtils;
@@ -117,11 +116,8 @@ public class Spawn extends CustomConfiguration {
                     }
                     break;
                 case "multiverse":
-                    if (Settings.multiverse && plugin.multiverse != null) {
+                    if (Settings.multiverse) {
-                        MVWorldManager manager = plugin.multiverse.getMVWorldManager();
+                        spawnLoc = plugin.getPluginHooks().getMultiverseSpawn(world);
-                        if (manager.isMVWorld(world)) {
-                            spawnLoc = manager.getMVWorld(world).getSpawnLocation();
-                        }
                     }
                     break;
                 case "essentials":

src/main/java/fr/xephi/authme/util/Utils.java

@@ -240,8 +240,7 @@ public final class Utils {
     }
 
     public static boolean isNPC(Player player) {
-        return player.hasMetadata("NPC") || plugin.combatTagPlus != null
+        return player.hasMetadata("NPC") || plugin.getPluginHooks().isNpcInCombatTagPlus(player);
-            && plugin.combatTagPlus.getNpcPlayerHelper().isNpc(player);
     }
 
     public static void teleportToSpawn(Player player) {

src/test/java/fr/xephi/authme/command/CommandServiceTest.java

@@ -1,9 +1,10 @@
 package fr.xephi.authme.command;
 
 import fr.xephi.authme.AuthMe;
+import fr.xephi.authme.cache.IpAddressManager;
 import fr.xephi.authme.command.help.HelpProvider;
 import fr.xephi.authme.datasource.DataSource;
-import fr.xephi.authme.cache.IpAddressManager;
+import fr.xephi.authme.hooks.PluginHooks;
 import fr.xephi.authme.output.MessageKey;
 import fr.xephi.authme.output.Messages;
 import fr.xephi.authme.permission.PermissionsManager;
@@ -42,6 +43,7 @@ public class CommandServiceTest {
     private PermissionsManager permissionsManager;
     private NewSetting settings;
     private IpAddressManager ipAddressManager;
+    private PluginHooks pluginHooks;
 
     @Before
     public void setUpService() {
@@ -53,8 +55,9 @@ public class CommandServiceTest {
         permissionsManager = mock(PermissionsManager.class);
         settings = mock(NewSetting.class);
         ipAddressManager = mock(IpAddressManager.class);
+        pluginHooks = mock(PluginHooks.class);
         commandService = new CommandService(authMe, commandMapper, helpProvider, messages, passwordSecurity,
-            permissionsManager, settings, ipAddressManager);
+            permissionsManager, settings, ipAddressManager, pluginHooks);
     }
 
     @Test