Java tutorial
/** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.hadoop.fs; import java.io.IOException; import java.io.ObjectInputStream; import java.io.Serializable; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.hdfs.protocol.LocatedBlock; /** * Wrapper for {@link BlockLocation} that also includes a {@link LocatedBlock}, * allowing more detailed queries to the datanode about a block. * */ @InterfaceAudience.Private @InterfaceStability.Unstable public class HdfsBlockLocation extends BlockLocation implements Serializable { private static final long serialVersionUID = 0x7aecec92; private transient LocatedBlock block; public HdfsBlockLocation(BlockLocation loc, LocatedBlock block) { // Initialize with data from passed in BlockLocation super(loc); this.block = block; } public LocatedBlock getLocatedBlock() { return block; } private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException { ois.defaultReadObject(); // LocatedBlock is not Serializable block = null; } }