Checking on unloading

core/src/main/java/mc/core/Location.java

@@ -5,15 +5,17 @@
 package mc.core;
 
 import lombok.Data;
+import mc.core.exception.ResourceUnloadException;
 import mc.core.world.World;
 
 import java.io.Serializable;
+import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 
 @Data
 public class Location implements Serializable{
     private double x, y, z;
-    private WeakReference<World> world;
+    private Reference<World> world;
 
     private static int floor_double(double value) {
         int i = (int)value;
@@ -53,6 +55,7 @@ public class Location implements Serializable{
 
     public Location(long compactValue, World world) {
         set(compactValue);
+        this.world = new WeakReference<>(world);
     }
 
     public void set(Location location) {
@@ -95,6 +98,9 @@ public class Location implements Serializable{
     }
 
     public World getWorld () {
+        if (world.get() == null) {
+            throw new ResourceUnloadException("You're trying to get unloaded world");
+        }
         return this.world.get();
     }
 

core/src/main/java/mc/core/exception/McCoreUncheckedException.java

@@ -0,0 +1,12 @@
+package mc.core.exception;
+
+public abstract class McCoreUncheckedException extends RuntimeException {
+
+    public McCoreUncheckedException() {
+        super();
+    }
+
+    public McCoreUncheckedException(String msg) {
+        super(msg);
+    }
+}

core/src/main/java/mc/core/exception/ResourceUnloadException.java

@@ -0,0 +1,8 @@
+package mc.core.exception;
+
+public class ResourceUnloadException extends McCoreUncheckedException {
+
+    public ResourceUnloadException(String msg) {
+        super(msg);
+    }
+}

generated_world/src/main/java/mc/world/generated_world/chunk/ChunkImpl.java

@@ -3,11 +3,13 @@ package mc.world.generated_world.chunk;
 import lombok.Getter;
 import mc.core.block.Block;
 import mc.core.block.BlockType;
+import mc.core.exception.ResourceUnloadException;
 import mc.core.world.Biome;
 import mc.core.world.Chunk;
 import mc.core.world.Region;
 import mc.core.world.World;
 
+import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 
 import static mc.world.generated_world.WorldConstants.WORLD_CHUNK_SIZE;
@@ -20,7 +22,7 @@ public class ChunkImpl implements Chunk{
     @Getter
     private final int z;
     private final Block[][][] blocks = new Block[WORLD_CHUNK_SIZE][WORLD_CHUNK_SIZE][WORLD_CHUNK_SIZE];
-    private final transient WeakReference<Region> region;
+    private final transient Reference<Region> region;
 
     public ChunkImpl(int x, int y, int z, Region region) {
         this.x = x;
@@ -109,6 +111,9 @@ public class ChunkImpl implements Chunk{
 
     @Override
     public Region getRegion() {
+        if (region.get() == null) {
+            throw new ResourceUnloadException("Region is unloaded");
+        }
         return region.get();
     }
 

generated_world/src/main/java/mc/world/generated_world/region/RegionImpl.java

@@ -3,6 +3,7 @@ package mc.world.generated_world.region;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import mc.core.exception.ResourceUnloadException;
 import mc.core.serialization.IRegionReaderWriter;
 import mc.core.serialization.Serializer;
 import mc.core.world.*;
@@ -14,6 +15,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.lang.ref.Reference;
 import java.lang.ref.WeakReference;
 import java.text.MessageFormat;
 
@@ -27,7 +29,7 @@ public class RegionImpl implements Region{
     private final int z;
     private final ChunkProxy[][][] chunks = new ChunkProxy[WORLD_REGION_SIZE/WORLD_CHUNK_SIZE][WORLD_REGION_SIZE/WORLD_CHUNK_SIZE][WORLD_REGION_SIZE/WORLD_CHUNK_SIZE];
     private final Biome[][] biomes = new Biome[WORLD_REGION_SIZE][WORLD_REGION_SIZE];
-    private final transient WeakReference<World> world;
+    private final transient Reference<World> world;
     @Autowired
     private ChunkLoader chunkLoader;
 
@@ -79,6 +81,9 @@ public class RegionImpl implements Region{
 
     @Override
     public World getWorld() {
+        if (world.get() == null) {
+            throw new ResourceUnloadException("World is unloaded");
+        }
         return world.get();
     }