Fix getOnlinePlayers call to support all versions

Moved IPlayerDataManager from api module to common module - it is not part of the API as there is no supported way to obtain an instance of it.

api/src/main/java/com/lishid/openinv/IOpenInv.java

@@ -7,6 +7,7 @@ import com.lishid.openinv.internal.ISpecialPlayerInventory;
 
 import org.bukkit.OfflinePlayer;
 import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
 
 /**
  * Interface defining behavior for the OpenInv plugin.
@@ -150,4 +151,37 @@ public interface IOpenInv {
      */
     public Player loadPlayer(final OfflinePlayer offline);
 
+    /**
+     * Mark a Player as in use by a Plugin to prevent it from being removed from the cache. Used to
+     * prevent issues with multiple copies of the same Player being loaded such as lishid#49.
+     * Changes made to loaded copies overwrite changes to the others when saved, leading to
+     * duplication bugs and more.
+     * <p>
+     * When finished with the Player object, be sure to call {@link #releasePlayer(Player, Plugin)}
+     * to prevent the cache from keeping it stored until the plugin is disabled.
+     * <p>
+     * When using a Player object from OpenInv, you must handle the Player coming online, replacing
+     * your Player reference with the Player from the PlayerJoinEvent. In addition, you must change
+     * any values in the Player to reflect any unsaved alterations to the existing Player which do
+     * not affect the inventory or ender chest contents.
+     * <p>
+     * OpenInv only saves player data when unloading a Player from the cache, and then only if
+     * {@link #disableSaving()} returns false. If you are making changes that OpenInv does not cause
+     * to persist when a Player logs in as noted above, it is suggested that you manually call
+     * {@link Player#saveData()} when releasing your reference to ensure your changes persist.
+     * 
+     * @param player the Player
+     * @param plugin the Plugin holding the reference to the Player
+     */
+    public void retainPlayer(Player player, Plugin plugin);
+
+    /**
+     * Mark a Player as no longer in use by a Plugin to allow OpenInv to remove it from the cache
+     * when eligible.
+     * 
+     * @param player the Player
+     * @param plugin the Plugin no longer holding a reference to the Player
+     */
+    public void releasePlayer(Player player, Plugin plugin);
+
 }

common/src/main/java/com/lishid/openinv/internal/IPlayerDataManager.java

@@ -16,6 +16,8 @@
 
 package com.lishid.openinv.internal;
 
+import java.util.Collection;
+
 import org.bukkit.OfflinePlayer;
 import org.bukkit.entity.Player;
 
@@ -47,4 +49,11 @@ public interface IPlayerDataManager {
      */
     public OfflinePlayer getPlayerByID(String identifier);
 
+    /**
+     * Gets a Collection of all Players currently online.
+     * 
+     * @return the Collection of Players
+     */
+    public Collection<? extends Player> getOnlinePlayers();
+
 }

internal/1_4_5/src/main/java/com/lishid/openinv/internal/v1_4_5/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_4_5;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/1_4_6/src/main/java/com/lishid/openinv/internal/v1_4_6/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_4_6;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_10_R1/src/main/java/com/lishid/openinv/internal/v1_10_R1/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_10_R1;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_11_R1/src/main/java/com/lishid/openinv/internal/v1_11_R1/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_11_R1;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_4_R1/src/main/java/com/lishid/openinv/internal/v1_4_R1/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_4_R1;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -70,4 +73,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_5_R2/src/main/java/com/lishid/openinv/internal/v1_5_R2/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_5_R2;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_5_R3/src/main/java/com/lishid/openinv/internal/v1_5_R3/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_5_R3;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_6_R1/src/main/java/com/lishid/openinv/internal/v1_6_R1/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_6_R1;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_6_R2/src/main/java/com/lishid/openinv/internal/v1_6_R2/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_6_R2;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_6_R3/src/main/java/com/lishid/openinv/internal/v1_6_R3/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_6_R3;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -69,4 +72,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_7_R1/src/main/java/com/lishid/openinv/internal/v1_7_R1/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_7_R1;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -70,4 +73,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_7_R2/src/main/java/com/lishid/openinv/internal/v1_7_R2/PlayerDataManager.java

@@ -16,6 +16,9 @@
 
 package com.lishid.openinv.internal.v1_7_R2;
 
+import java.util.Arrays;
+import java.util.Collection;
+
 import com.lishid.openinv.internal.IPlayerDataManager;
 
 import org.bukkit.Bukkit;
@@ -71,4 +74,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         return player;
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_7_R3/src/main/java/com/lishid/openinv/internal/v1_7_R3/PlayerDataManager.java

@@ -16,6 +16,8 @@
 
 package com.lishid.openinv.internal.v1_7_R3;
 
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -78,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Arrays.asList(Bukkit.getOnlinePlayers());
+    }
+
 }

internal/v1_7_R4/pom.xml

@@ -17,6 +17,12 @@
       <artifactId>openinvcommon</artifactId>
       <version>1.0-SNAPSHOT</version>
     </dependency>
+    <dependency>
+      <groupId>org.spigotmc</groupId>
+      <artifactId>spigot-api</artifactId>
+      <version>1.7.10-R0.1-snapshot</version>
+      <scope>provided</scope>
+    </dependency>
     <dependency>
       <groupId>org.bukkit</groupId>
       <artifactId>craftbukkit</artifactId>

internal/v1_7_R4/src/main/java/com/lishid/openinv/internal/v1_7_R4/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_7_R4;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -78,4 +79,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_8_R1/src/main/java/com/lishid/openinv/internal/v1_8_R1/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_8_R1;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_8_R2/src/main/java/com/lishid/openinv/internal/v1_8_R2/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_8_R2;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_8_R3/src/main/java/com/lishid/openinv/internal/v1_8_R3/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_8_R3;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_9_R1/src/main/java/com/lishid/openinv/internal/v1_9_R1/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_9_R1;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

internal/v1_9_R2/src/main/java/com/lishid/openinv/internal/v1_9_R2/PlayerDataManager.java

@@ -16,6 +16,7 @@
 
 package com.lishid.openinv.internal.v1_9_R2;
 
+import java.util.Collection;
 import java.util.UUID;
 
 import com.lishid.openinv.internal.IPlayerDataManager;
@@ -79,4 +80,9 @@ public class PlayerDataManager implements IPlayerDataManager {
         }
     }
 
+    @Override
+    public Collection<? extends Player> getOnlinePlayers() {
+        return Bukkit.getOnlinePlayers();
+    }
+
 }

plugin/plugin-core/src/main/java/com/lishid/openinv/OpenInv.java

@@ -16,6 +16,10 @@
 
 package com.lishid.openinv;
 
+import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -38,18 +42,23 @@ import com.lishid.openinv.internal.ISpecialPlayerInventory;
 import com.lishid.openinv.listeners.InventoryClickListener;
 import com.lishid.openinv.listeners.InventoryDragListener;
 import com.lishid.openinv.listeners.PlayerListener;
+import com.lishid.openinv.listeners.PluginListener;
 import com.lishid.openinv.util.Cache;
 import com.lishid.openinv.util.ConfigUpdater;
 import com.lishid.openinv.util.Function;
 import com.lishid.openinv.util.InternalAccessor;
 import com.lishid.openinv.util.Permissions;
 
+import com.google.common.collect.HashMultimap;
+import com.google.common.collect.Multimap;
+
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.command.PluginCommand;
 import org.bukkit.entity.HumanEntity;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.Inventory;
+import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.java.JavaPlugin;
 import org.bukkit.scheduler.BukkitRunnable;
@@ -63,13 +72,16 @@ public class OpenInv extends JavaPlugin implements IOpenInv {
 
     private final Map<String, ISpecialPlayerInventory> inventories = new HashMap<String, ISpecialPlayerInventory>();
     private final Map<String, ISpecialEnderChest> enderChests = new HashMap<String, ISpecialEnderChest>();
+    private final Multimap<String, Class<? extends Plugin>> pluginUsage = HashMultimap.create();
+
     private final Cache<String, Player> playerCache = new Cache<String, Player>(300000L,
             new Function<Player>() {
                 @Override
                 public boolean run(Player value) {
                     String key = playerLoader.getPlayerDataID(value);
                     return inventories.containsKey(key) && inventories.get(key).isInUse()
-                            || enderChests.containsKey(key) && enderChests.get(key).isInUse();
+                            || enderChests.containsKey(key) && enderChests.get(key).isInUse()
+                            || pluginUsage.containsKey(key);
                 }
             },
             new Function<Player>() {
@@ -127,6 +139,7 @@ public class OpenInv extends JavaPlugin implements IOpenInv {
 
         // Register listeners
         pm.registerEvents(new PlayerListener(this), this);
+        pm.registerEvents(new PluginListener(this), this);
         pm.registerEvents(new InventoryClickListener(this), this);
         // Bukkit will handle missing events for us, attempt to register InventoryDragEvent without a version check
         pm.registerEvents(new InventoryDragListener(this), this);
@@ -134,10 +147,10 @@ public class OpenInv extends JavaPlugin implements IOpenInv {
         // Register commands to their executors
         getCommand("openinv").setExecutor(new OpenInvPluginCommand(this));
         getCommand("openender").setExecutor(new OpenEnderPluginCommand(this));
-        SearchInvPluginCommand searchInv = new SearchInvPluginCommand();
+        SearchInvPluginCommand searchInv = new SearchInvPluginCommand(this);
         getCommand("searchinv").setExecutor(searchInv);
         getCommand("searchender").setExecutor(searchInv);
-        getCommand("searchenchant").setExecutor(new SearchEnchantPluginCommand());
+        getCommand("searchenchant").setExecutor(new SearchEnchantPluginCommand(this));
         getCommand("silentchest").setExecutor(new SilentChestPluginCommand(this));
         getCommand("anychest").setExecutor(new AnyChestPluginCommand(this));
 
@@ -427,6 +440,7 @@ public class OpenInv extends JavaPlugin implements IOpenInv {
             return this.playerCache.get(key);
         }
 
+        // TODO: wrap Player to ensure all methods can safely be called offline
         Player loaded;
 
         if (offline.isOnline()) {
@@ -479,6 +493,73 @@ public class OpenInv extends JavaPlugin implements IOpenInv {
         return loaded;
     }
 
+    /**
+     * @see com.lishid.openinv.IOpenInv#retainPlayer(org.bukkit.entity.Player, org.bukkit.plugin.Plugin)
+     */
+    @Override
+    public void retainPlayer(Player player, Plugin plugin) {
+        String key = this.playerLoader.getPlayerDataID(player);
+
+        if (this.pluginUsage.containsEntry(key, plugin.getClass())) {
+            return;
+        }
+
+        this.pluginUsage.put(key, plugin.getClass());
+    }
+
+    /**
+     * @see com.lishid.openinv.IOpenInv#releasePlayer(org.bukkit.entity.Player, org.bukkit.plugin.Plugin)
+     */
+    @Override
+    public void releasePlayer(Player player, Plugin plugin) {
+        String key = this.playerLoader.getPlayerDataID(player);
+
+        if (!this.pluginUsage.containsEntry(key, plugin.getClass())) {
+            return;
+        }
+
+        this.pluginUsage.remove(key, plugin.getClass());
+    }
+
+    /**
+     * Unmark any Players in use by the specified Plugin.
+     * 
+     * @param plugin
+     */
+    public void releaseAllPlayers(Plugin plugin) {
+        this.pluginUsage.removeAll(plugin.getClass());
+    }
+
+    @SuppressWarnings("unchecked")
+    public Collection<? extends Player> getOnlinePlayers() {
+
+        if (this.playerLoader != null) {
+            return this.playerLoader.getOnlinePlayers();
+        }
+
+        Method getOnlinePlayers;
+        try {
+            getOnlinePlayers = Bukkit.class.getDeclaredMethod("getOnlinePlayers");
+        } catch (Exception e) {
+            e.printStackTrace();
+            return Collections.emptyList();
+        }
+
+        Object onlinePlayers;
+        try {
+            onlinePlayers = getOnlinePlayers.invoke(null);
+        } catch (Exception e) {
+            e.printStackTrace();
+            return Collections.emptyList();
+        }
+
+        if (onlinePlayers instanceof List) {
+            return (Collection<Player>) onlinePlayers;
+        }
+
+        return Arrays.asList((Player[]) onlinePlayers);
+    }
+
     /**
      * Method for handling a Player coming online.
      * 

plugin/plugin-core/src/main/java/com/lishid/openinv/commands/SearchEnchantPluginCommand.java

@@ -1,6 +1,7 @@
 package com.lishid.openinv.commands;
 
-import org.bukkit.Bukkit;
+import com.lishid.openinv.OpenInv;
+
 import org.bukkit.Material;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
@@ -19,6 +20,12 @@ import org.bukkit.inventory.meta.ItemMeta;
  */
 public class SearchEnchantPluginCommand implements CommandExecutor {
 
+    private final OpenInv plugin;
+
+    public SearchEnchantPluginCommand(OpenInv plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
         if (args.length == 0) {
@@ -45,7 +52,7 @@ public class SearchEnchantPluginCommand implements CommandExecutor {
         }
 
         StringBuilder players = new StringBuilder();
-        for (Player player : Bukkit.getServer().getOnlinePlayers()) {
+        for (Player player : plugin.getOnlinePlayers()) {
             boolean flagInventory = containsEnchantment(player.getInventory(), enchant, level);
             boolean flagEnder = containsEnchantment(player.getEnderChest(), enchant, level);
 

plugin/plugin-core/src/main/java/com/lishid/openinv/commands/SearchInvPluginCommand.java

@@ -16,7 +16,8 @@
 
 package com.lishid.openinv.commands;
 
-import org.bukkit.Bukkit;
+import com.lishid.openinv.OpenInv;
+
 import org.bukkit.ChatColor;
 import org.bukkit.Material;
 import org.bukkit.command.Command;
@@ -27,6 +28,12 @@ import org.bukkit.inventory.Inventory;
 
 public class SearchInvPluginCommand implements CommandExecutor {
 
+    private final OpenInv plugin;
+
+    public SearchInvPluginCommand(OpenInv plugin) {
+        this.plugin = plugin;
+    }
+
     @Override
     public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
 
@@ -54,7 +61,7 @@ public class SearchInvPluginCommand implements CommandExecutor {
         }
 
         StringBuilder players = new StringBuilder();
-        for (Player player : Bukkit.getServer().getOnlinePlayers()) {
+        for (Player player : plugin.getOnlinePlayers()) {
             Inventory inventory = command.getName().equals("searchinv") ? player.getInventory() : player.getEnderChest();
             if (inventory.contains(material, count)) {
                 players.append(player.getName()).append(", ");

plugin/plugin-core/src/main/java/com/lishid/openinv/listeners/PluginListener.java

@@ -0,0 +1,27 @@
+package com.lishid.openinv.listeners;
+
+import com.lishid.openinv.OpenInv;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.server.PluginDisableEvent;
+
+/**
+ * Listener for plugin-related events.
+ * 
+ * @author Jikoo
+ */
+public class PluginListener implements Listener {
+
+    private final OpenInv plugin;
+
+    public PluginListener(OpenInv plugin) {
+        this.plugin = plugin;
+    }
+
+    @EventHandler
+    public void onPluginDisable(PluginDisableEvent event) {
+        plugin.releaseAllPlayers(event.getPlugin());
+    }
+
+}

pom.xml

@@ -12,7 +12,7 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-    <openinv.version>3.0.3-SNAPSHOT</openinv.version>
+    <openinv.version>3.0.4-SNAPSHOT</openinv.version>
   </properties>
 
   <modules>