Improve stability of instantiation system

src/main/java/de/erethon/dungeonsxl/DungeonsXL.java

@@ -36,7 +36,6 @@ import de.erethon.dungeonsxl.mob.DMobListener;
 import de.erethon.dungeonsxl.mob.DMobType;
 import de.erethon.dungeonsxl.mob.ExternalMobProviderCache;
 import de.erethon.dungeonsxl.player.DClassCache;
-import de.erethon.dungeonsxl.player.DGamePlayer;
 import de.erethon.dungeonsxl.player.DGroup;
 import de.erethon.dungeonsxl.player.DPermission;
 import de.erethon.dungeonsxl.player.DPlayerCache;
@@ -139,11 +138,6 @@ public class DungeonsXL extends DREPlugin {
         saveData();
         messageConfig.save();
 
-        // DGamePlayer leaves World
-        for (DGamePlayer dPlayer : dPlayers.getDGamePlayers()) {
-            dPlayer.leave();
-        }
-
         dGroups.clear();
 
         // Delete DWorlds

src/main/java/de/erethon/dungeonsxl/world/DEditWorld.java

@@ -20,7 +20,6 @@ import de.erethon.commons.misc.FileUtil;
 import de.erethon.dungeonsxl.DungeonsXL;
 import de.erethon.dungeonsxl.event.editworld.EditWorldSaveEvent;
 import de.erethon.dungeonsxl.event.editworld.EditWorldUnloadEvent;
-import de.erethon.dungeonsxl.player.DEditPlayer;
 import java.io.File;
 import java.io.IOException;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -28,7 +27,6 @@ import org.bukkit.Bukkit;
 import org.bukkit.World;
 import org.bukkit.block.Block;
 import org.bukkit.block.Sign;
-import org.bukkit.entity.Player;
 import org.bukkit.scheduler.BukkitRunnable;
 
 /**
@@ -157,10 +155,7 @@ public class DEditWorld extends DInstanceWorld {
             return;
         }
 
-        for (Player player : getWorld().getPlayers()) {
+        kickAllPlayers();
-            DEditPlayer dPlayer = DEditPlayer.getByPlayer(player);
-            dPlayer.leave();
-        }
 
         if (!plugin.getMainConfig().areTweaksEnabled()) {
             if (save) {

src/main/java/de/erethon/dungeonsxl/world/DGameWorld.java

@@ -496,6 +496,8 @@ public class DGameWorld extends DInstanceWorld {
             return;
         }
 
+        kickAllPlayers();
+
         if (!plugin.getMainConfig().areTweaksEnabled()) {
             Bukkit.unloadWorld(getWorld(), false);
             FileUtil.removeDir(getFolder());
@@ -552,6 +554,9 @@ public class DGameWorld extends DInstanceWorld {
         Player player = event.getPlayer();
         Block block = event.getBlock();
         for (DSign dSign : dSigns) {
+            if (dSign == null) {
+                continue;
+            }
             if ((block.equals(dSign.getSign().getBlock()) || block.equals(BlockUtil.getAttachedBlock(dSign.getSign().getBlock()))) && dSign.getType().isProtected()) {
                 return true;
             }

src/main/java/de/erethon/dungeonsxl/world/DInstanceWorld.java

@@ -17,10 +17,15 @@
 package de.erethon.dungeonsxl.world;
 
 import de.erethon.commons.chat.MessageUtil;
+import de.erethon.commons.player.PlayerUtil;
 import de.erethon.dungeonsxl.DungeonsXL;
 import de.erethon.dungeonsxl.game.GameRuleProvider;
 import de.erethon.dungeonsxl.player.DGamePlayer;
+import de.erethon.dungeonsxl.player.DInstancePlayer;
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Collection;
+import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.World;
 
@@ -114,6 +119,20 @@ public abstract class DInstanceWorld {
         this.lobby = lobby;
     }
 
+    /**
+     * @return
+     * the players in this world
+     */
+    public Collection<DInstancePlayer> getPlayers() {
+        Collection<DInstancePlayer> players = new ArrayList<>();
+        for (DInstancePlayer player : plugin.getDPlayers().getDInstancePlayers()) {
+            if (player.getWorld().equals(world)) {
+                players.add(player);
+            }
+        }
+        return players;
+    }
+
     /* Actions */
     /**
      * Sends a message to all players in the instance.
@@ -127,6 +146,17 @@ public abstract class DInstanceWorld {
         }
     }
 
+    /**
+     * Makes all players leave the world.
+     * Attempts to let them leave properly if they are correct DInstancePlayers;
+     * teleports them to the spawn if they are not.
+     */
+    public void kickAllPlayers() {
+        getPlayers().forEach(p -> p.leave());
+        // Players who shouldn't be in the dungeon but still are for some reason
+        world.getPlayers().forEach(p -> PlayerUtil.secureTeleport(p, Bukkit.getWorlds().get(0).getSpawnLocation()));
+    }
+
     /**
      * @param rules
      * sets up the time and weather to match the rules

src/main/java/de/erethon/dungeonsxl/world/DResourceWorld.java

@@ -16,6 +16,7 @@
  */
 package de.erethon.dungeonsxl.world;
 
+import de.erethon.commons.chat.MessageUtil;
 import de.erethon.commons.misc.FileUtil;
 import de.erethon.commons.worldloader.WorldLoader;
 import de.erethon.dungeonsxl.DungeonsXL;
@@ -25,6 +26,7 @@ import java.io.File;
 import java.io.IOException;
 import org.bukkit.Bukkit;
 import org.bukkit.OfflinePlayer;
+import org.bukkit.World;
 import org.bukkit.World.Environment;
 import org.bukkit.WorldCreator;
 import org.bukkit.WorldType;
@@ -209,12 +211,24 @@ public class DResourceWorld {
     public DInstanceWorld instantiate(final boolean game) {
         int id = worlds.generateId();
         String name = worlds.generateName(game, id);
-        final File instanceFolder = new File(Bukkit.getWorldContainer(), name);
+        File tempIF = new File(Bukkit.getWorldContainer(), name);
-
+        while (tempIF.exists()) {
-        while (Bukkit.getWorld(name) != null) {
+            World world = Bukkit.getWorld(name);
+            boolean removed = false;
+            if (world != null && world.getPlayers().isEmpty()) {
+                Bukkit.unloadWorld(name, false);
+            }
+            if (world == null || world.getPlayers().isEmpty()) {
+                removed = tempIF.delete();
+            }
+            if (!removed) {
+                MessageUtil.log(plugin, "&6Warning: An unrecognized junk instance (&4" + name + "&6) has been found, but could not be deleted.");
                 id++;
                 name = worlds.generateName(game, id);
+                tempIF = new File(Bukkit.getWorldContainer(), name);
             }
+        }
+        final File instanceFolder = tempIF; // Because Java SUCKS
 
         final DInstanceWorld instance = game ? new DGameWorld(this, instanceFolder, id) : new DEditWorld(this, instanceFolder, id);
 
@@ -263,7 +277,6 @@ public class DResourceWorld {
         }
 
         DEditWorld editWorld = (DEditWorld) instantiate(false);
-        editWorld.generateIdFile();
         return editWorld;
     }
 
@@ -306,6 +319,7 @@ public class DResourceWorld {
                     FileUtil.copyDir(DWorldCache.RAW, folder, DungeonsXL.EXCLUDED_FILES);
                     editWorld.generateIdFile();
                     editWorld.world = WorldLoader.createWorld(creator);
+                    editWorld.generateIdFile();
                 }
             }.runTaskAsynchronously(plugin);
         }

src/main/java/de/erethon/dungeonsxl/world/DWorldCache.java

@@ -211,14 +211,22 @@ public class DWorldCache {
      */
     public void check() {
         for (File file : Bukkit.getWorldContainer().listFiles()) {
-            if (file.getName().startsWith("DXL_Edit_") && file.isDirectory()) {
+            if (!file.getName().startsWith("DXL_") || !file.isDirectory()) {
+                continue;
+            }
+
+            if (file.getName().startsWith("DXL_Edit_")) {
                 for (File mapFile : file.listFiles()) {
-                    if (mapFile.getName().startsWith(".id_")) {
+                    if (!mapFile.getName().startsWith(".id_")) {
+                        continue;
+                    }
+
                     String name = mapFile.getName().substring(4);
 
                     File resource = new File(DungeonsXL.MAPS, name);
                     File backup = new File(DungeonsXL.BACKUPS, resource.getName() + "-" + System.currentTimeMillis() + "_crashbackup");
                     FileUtil.copyDir(resource, backup);
+                    // Remove all files from the backupped resource world but not the config & data that we cannot fetch from the instance.
                     remove:
                     for (File remove : FileUtil.getFilesForFolder(resource)) {
                         for (String nope : DungeonsXL.EXCLUDED_FILES) {
@@ -230,16 +238,12 @@ public class DWorldCache {
                     }
                     deleteUnusedFiles(file);
                     FileUtil.copyDir(file, resource, DungeonsXL.EXCLUDED_FILES);
-
-                        FileUtil.removeDir(file);
                 }
             }
 
-            } else if (file.getName().startsWith("DXL_Game_") && file.isDirectory()) {
             FileUtil.removeDir(file);
         }
     }
-    }
 
     /**
      * Clean up all instances.