HCFS: add close() to SeaweedFileSystem.java

other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystem.java

@@ -65,6 +65,12 @@ public class SeaweedFileSystem extends FileSystem {
 
     }
 
+    @Override
+    public void close() throws IOException {
+        this.seaweedFileSystemStore.close();
+        super.close();
+    }
+
     @Override
     public FSDataInputStream open(Path path, int bufferSize) throws IOException {
 

other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java

@@ -36,6 +36,14 @@ public class SeaweedFileSystemStore {
         this.conf = conf;
     }
 
+    public void close() {
+        try {
+            this.filerGrpcClient.shutdown();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+    }
+
     public static String getParentDirectory(Path path) {
         return path.isRoot() ? "/" : path.getParent().toUri().getPath();
     }