/*
* JBoss, Home of Professional Open Source
*
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @author tags. See the COPYRIGHT.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.netty.handler.codec.serialization;
import static org.jboss.netty.buffer.ChannelBuffers.*;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBufferOutputStream;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipelineCoverage;
import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
/**
* An encoder which serializes a Java object into a {@link ChannelBuffer}.
* <p>
* Please note that the serialized form this encoder produces is not
* compatible with the standard {@link ObjectInputStream}. Please use
* {@link ObjectDecoder} or {@link ObjectDecoderInputStream} to ensure the
* interoperability with this encoder.
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Trustin Lee (tlee@redhat.com)
*
* @version $Rev:231 $, $Date:2008-06-12 16:44:50 +0900 (목, 12 6월 2008) $
*
* @apiviz.landmark
*/
@ChannelPipelineCoverage("all")
public class ObjectEncoder extends OneToOneEncoder {
private static final byte[] LENGTH_PLACEHOLDER = new byte[4];
private final int estimatedLength;
/**
* Creates a new encoder with the estimated length of 512 bytes.
*/
public ObjectEncoder() {
this(512);
}
/**
* Creates a new encoder.
*
* @param estimatedLength
* the estimated byte length of the serialized form of an object.
* If the length of the serialized form exceeds this value, the
* internal buffer will be expanded automatically at the cost of
* memory bandwidth. If this value is too big, it will also waste
* memory bandwidth. To avoid unnecessary memory copy or allocation
* cost, please specify the properly estimated value.
*/
public ObjectEncoder(int estimatedLength) {
if (estimatedLength < 0) {
throw new IllegalArgumentException(
"estimatedLength: " + estimatedLength);
}
this.estimatedLength = estimatedLength;
}
@Override
protected Object encode(ChannelHandlerContext ctx, Channel channel, Object msg) throws Exception {
ChannelBufferOutputStream bout =
new ChannelBufferOutputStream(dynamicBuffer(
estimatedLength, ctx.getChannel().getConfig().getBufferFactory()));
bout.write(LENGTH_PLACEHOLDER);
ObjectOutputStream oout = new CompactObjectOutputStream(bout);
oout.writeObject(msg);
oout.flush();
oout.close();
ChannelBuffer encoded = bout.buffer();
encoded.setInt(0, encoded.writerIndex() - 4);
return encoded;
}
}