Fix use of implementation-specific exception

BlueMapCommon/src/main/java/de/bluecolored/bluemap/common/plugin/MapUpdateService.java

@@ -32,7 +32,6 @@
 import de.bluecolored.bluemap.core.util.WatchService;
 
 import java.io.IOException;
-import java.nio.file.ClosedWatchServiceException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Timer;
@@ -67,7 +66,7 @@ public void run() {
         try {
             while (!closed)
                 this.watchService.take().forEach(this::updateRegion);
-        } catch (ClosedWatchServiceException ignore) {
+        } catch (WatchService.ClosedException ignore) {
         } catch (InterruptedException iex) {
             Thread.currentThread().interrupt();
         } finally {

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/util/WatchService.java

@@ -24,6 +24,7 @@
  */
 package de.bluecolored.bluemap.core.util;
 
+import lombok.experimental.StandardException;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -35,11 +36,33 @@
  */
 public interface WatchService<T> extends AutoCloseable {
 
+    /**
+     * Retrieves and consumes the next batch of events.
+     * @throws ClosedException If the watch-service is closed
+     */
     @Nullable
     List<T> poll();
 
+    /**
+     * Retrieves and consumes the next batch of events,
+     * waiting if necessary up to the specified wait time if none are yet present.
+     * @throws ClosedException If the watch-service is closed, or it is closed while waiting for the next event
+     * @throws InterruptedException If interrupted while waiting
+     */
     @Nullable List<T> poll(long timeout, TimeUnit unit) throws InterruptedException;
 
+    /**
+     * Retrieves and consumes the next batch of events,
+     * waiting if necessary until an event becomes available.
+     * @throws ClosedException If the watch-service is closed, or it is closed while waiting for the next event
+     * @throws InterruptedException If interrupted while waiting
+     */
     List<T> take() throws InterruptedException;
 
+    /**
+     * Thrown when the WatchService is closed or gets closed when polling or while waiting for events
+     */
+    @StandardException
+    class ClosedException extends RuntimeException {}
+
 }

BlueMapCore/src/main/java/de/bluecolored/bluemap/core/world/mca/MCAWorldRegionWatchService.java

@@ -30,6 +30,7 @@
 import org.jetbrains.annotations.Nullable;
 
 import java.io.IOException;
+import java.nio.file.ClosedWatchServiceException;
 import java.nio.file.Path;
 import java.nio.file.StandardWatchEventKinds;
 import java.nio.file.WatchKey;
@@ -52,22 +53,34 @@ public MCAWorldRegionWatchService(Path regionFolder) throws IOException {
 
     @Override
     public @Nullable List<Vector2i> poll() {
-        WatchKey key = watchService.poll();
-        if (key == null) return null;
-        return processWatchKey(key);
+        try {
+            WatchKey key = watchService.poll();
+            if (key == null) return null;
+            return processWatchKey(key);
+        } catch (ClosedWatchServiceException e) {
+            throw new ClosedException(e);
+        }
     }
 
     @Override
     public @Nullable List<Vector2i> poll(long timeout, TimeUnit unit) throws InterruptedException {
-        WatchKey key = watchService.poll(timeout, unit);
-        if (key == null) return null;
-        return processWatchKey(key);
+        try {
+            WatchKey key = watchService.poll(timeout, unit);
+            if (key == null) return null;
+            return processWatchKey(key);
+        } catch (ClosedWatchServiceException e) {
+            throw new ClosedException(e);
+        }
     }
 
     @Override
     public List<Vector2i> take() throws InterruptedException {
-        WatchKey key = watchService.take();
-        return processWatchKey(key);
+        try {
+            WatchKey key = watchService.take();
+            return processWatchKey(key);
+        } catch (ClosedWatchServiceException e) {
+            throw new ClosedException(e);
+        }
     }
 
     @Override