/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 io.netty.handler.codec.serialization;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufOutputStream;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import io.netty.util.Attribute;
import io.netty.util.AttributeKey;

import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;

An encoder which serializes a Java object into a ByteBuf (interoperability version).

This encoder is interoperable with the standard Java object streams such as ObjectInputStream and ObjectOutputStream.

/** * An encoder which serializes a Java object into a {@link ByteBuf} * (interoperability version). * <p> * This encoder is interoperable with the standard Java object streams such as * {@link ObjectInputStream} and {@link ObjectOutputStream}. */
public class CompatibleObjectEncoder extends MessageToByteEncoder<Serializable> { private final int resetInterval; private int writtenObjects;
Creates a new instance with the reset interval of 16.
/** * Creates a new instance with the reset interval of {@code 16}. */
public CompatibleObjectEncoder() { this(16); // Reset at every sixteen writes }
Creates a new instance.
Params:
/** * Creates a new instance. * * @param resetInterval * the number of objects between {@link ObjectOutputStream#reset()}. * {@code 0} will disable resetting the stream, but the remote * peer will be at the risk of getting {@link OutOfMemoryError} in * the long term. */
public CompatibleObjectEncoder(int resetInterval) { if (resetInterval < 0) { throw new IllegalArgumentException( "resetInterval: " + resetInterval); } this.resetInterval = resetInterval; }
Creates a new ObjectOutputStream which wraps the specified OutputStream. Override this method to use a subclass of the ObjectOutputStream.
/** * Creates a new {@link ObjectOutputStream} which wraps the specified * {@link OutputStream}. Override this method to use a subclass of the * {@link ObjectOutputStream}. */
protected ObjectOutputStream newObjectOutputStream(OutputStream out) throws Exception { return new ObjectOutputStream(out); } @Override protected void encode(ChannelHandlerContext ctx, Serializable msg, ByteBuf out) throws Exception { ObjectOutputStream oos = newObjectOutputStream(new ByteBufOutputStream(out)); try { if (resetInterval != 0) { // Resetting will prevent OOM on the receiving side. writtenObjects ++; if (writtenObjects % resetInterval == 0) { oos.reset(); } } oos.writeObject(msg); oos.flush(); } finally { oos.close(); } } }