001/** 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.apache.hadoop.io.serializer; 020 021import java.io.IOException; 022import java.io.InputStream; 023import java.io.ObjectInputStream; 024import java.io.ObjectOutputStream; 025import java.io.OutputStream; 026import java.io.Serializable; 027import org.apache.hadoop.classification.InterfaceAudience; 028import org.apache.hadoop.classification.InterfaceStability; 029 030/** 031 * <p> 032 * An experimental {@link Serialization} for Java {@link Serializable} classes. 033 * </p> 034 * @see JavaSerializationComparator 035 */ 036@InterfaceAudience.Public 037@InterfaceStability.Unstable 038public class JavaSerialization implements Serialization<Serializable> { 039 040 static class JavaSerializationDeserializer<T extends Serializable> 041 implements Deserializer<T> { 042 043 private ObjectInputStream ois; 044 045 @Override 046 public void open(InputStream in) throws IOException { 047 ois = new ObjectInputStream(in) { 048 @Override protected void readStreamHeader() { 049 // no header 050 } 051 }; 052 } 053 054 @Override 055 @SuppressWarnings("unchecked") 056 public T deserialize(T object) throws IOException { 057 try { 058 // ignore passed-in object 059 return (T) ois.readObject(); 060 } catch (ClassNotFoundException e) { 061 throw new IOException(e.toString()); 062 } 063 } 064 065 @Override 066 public void close() throws IOException { 067 ois.close(); 068 } 069 070 } 071 072 static class JavaSerializationSerializer 073 implements Serializer<Serializable> { 074 075 private ObjectOutputStream oos; 076 077 @Override 078 public void open(OutputStream out) throws IOException { 079 oos = new ObjectOutputStream(out) { 080 @Override protected void writeStreamHeader() { 081 // no header 082 } 083 }; 084 } 085 086 @Override 087 public void serialize(Serializable object) throws IOException { 088 oos.reset(); // clear (class) back-references 089 oos.writeObject(object); 090 } 091 092 @Override 093 public void close() throws IOException { 094 oos.close(); 095 } 096 097 } 098 099 @Override 100 @InterfaceAudience.Private 101 public boolean accept(Class<?> c) { 102 return Serializable.class.isAssignableFrom(c); 103 } 104 105 @Override 106 @InterfaceAudience.Private 107 public Deserializer<Serializable> getDeserializer(Class<Serializable> c) { 108 return new JavaSerializationDeserializer<Serializable>(); 109 } 110 111 @Override 112 @InterfaceAudience.Private 113 public Serializer<Serializable> getSerializer(Class<Serializable> c) { 114 return new JavaSerializationSerializer(); 115 } 116 117}