Quarantines duplicate islands so they don't load continuously

https://github.com/BentoBoxWorld/BentoBox/issues/505

src/main/java/world/bentobox/bentobox/database/objects/Island.java

@@ -107,6 +107,12 @@ public class Island implements DataObject {
     private int levelHandicap;
     @Expose
     private Map<Environment, Location> spawnPoint = new EnumMap<>(Environment.class);
+    
+    /**
+     * This flag is used to quarantine islands that cannot be loaded and should be purged at some point
+     */
+    @Expose
+    private boolean doNotLoad;
 
     public Island() {}
 
@@ -801,4 +807,18 @@ public class Island implements DataObject {
     public void setHistory(List<LogEntry> history) {
         this.history = history;
     }
+
+    /**
+     * @return the doNotLoad
+     */
+    public boolean isDoNotLoad() {
+        return doNotLoad;
+    }
+
+    /**
+     * @param doNotLoad the doNotLoad to set
+     */
+    public void setDoNotLoad(boolean doNotLoad) {
+        this.doNotLoad = doNotLoad;
+    }
 }

src/main/java/world/bentobox/bentobox/managers/IslandsManager.java

@@ -1,7 +1,9 @@
 package world.bentobox.bentobox.managers;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -22,9 +24,9 @@ import org.bukkit.entity.Monster;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.util.Vector;
-
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
+
 import world.bentobox.bentobox.BentoBox;
 import world.bentobox.bentobox.api.events.IslandBaseEvent;
 import world.bentobox.bentobox.api.events.island.IslandEvent;
@@ -32,8 +34,8 @@ import world.bentobox.bentobox.api.events.island.IslandEvent.Reason;
 import world.bentobox.bentobox.api.localization.TextVariables;
 import world.bentobox.bentobox.api.user.User;
 import world.bentobox.bentobox.database.Database;
-import world.bentobox.bentobox.database.objects.IslandDeletion;
 import world.bentobox.bentobox.database.objects.Island;
+import world.bentobox.bentobox.database.objects.IslandDeletion;
 import world.bentobox.bentobox.lists.Flags;
 import world.bentobox.bentobox.managers.island.IslandCache;
 import world.bentobox.bentobox.util.DeleteIslandChunks;
@@ -696,7 +698,22 @@ public class IslandsManager {
      */
     public void load(){
         islandCache.clear();
-        handler.loadObjects().forEach(islandCache::addIsland);
+        List<Island> toQuarantine = new ArrayList<>();
+        // Only load non-quarantined island
+        // TODO: write a purge admin command to delete these records
+        handler.loadObjects().stream().filter(i -> !i.isDoNotLoad()).forEach(island -> {
+           if (!islandCache.addIsland(island)) {
+               // Quarantine the offending island
+               toQuarantine.add(island);
+           }
+        });
+        if (!toQuarantine.isEmpty()) {
+            plugin.logError(toQuarantine.size() + " islands could not be loaded successfully; quarantining.");
+            toQuarantine.forEach(i -> {
+                i.setDoNotLoad(true);
+                handler.saveObject(i);
+            });          
+        }
     }
 
     /**

src/main/java/world/bentobox/bentobox/managers/island/IslandCache.java

@@ -45,15 +45,18 @@ public class IslandCache {
         if (island.getCenter() == null || island.getWorld() == null) {
             return false;
         }
-        islandsByLocation.put(island.getCenter(), island);
-        // Make world
-        islandsByUUID.putIfAbsent(island.getWorld(), new HashMap<>());
-        // Only add islands to this map if they are owned
-        if (island.getOwner() != null) {
-            islandsByUUID.get(island.getWorld()).put(island.getOwner(), island);
-            island.getMemberSet().forEach(member -> islandsByUUID.get(island.getWorld()).put(member, island));
+        if (addToGrid(island)) {
+            islandsByLocation.put(island.getCenter(), island);
+            // Make world
+            islandsByUUID.putIfAbsent(island.getWorld(), new HashMap<>());
+            // Only add islands to this map if they are owned
+            if (island.getOwner() != null) {
+                islandsByUUID.get(island.getWorld()).put(island.getOwner(), island);
+                island.getMemberSet().forEach(member -> islandsByUUID.get(island.getWorld()).put(member, island));
+            }
+            return true;
         }
-        return addToGrid(island);
+        return false;
     }
 
     /**

src/main/resources/plugin.yml

@@ -6,10 +6,10 @@ api-version: 1.13
 authors: [tastybento, Poslovitch]
 website: https://bentobox.world
 
-softdepend: [Vault, PlaceholderAPI, MVdWPlaceholderAPI]
-
 loadbefore: [Multiverse-Core]
 
+softdepend: [Vault, PlaceholderAPI, MVdWPlaceholderAPI]
+
 permissions:    
   bentobox.admin:
    description: Allow bentobox command usage