/*
* Copyright 2009 Red Hat, Inc.
*
* Red Hat 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.jboss.netty.example.factorial;
import java.math.BigInteger;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
/**
* Handler for a client-side channel. This handler maintains stateful
* information which is specific to a certain channel using member variables.
* Therefore, an instance of this handler can cover only one channel. You have
* to create a new handler instance whenever you create a new channel and insert
* this handler to avoid a race condition.
*
* @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
* @author <a href="http://gleamynode.net/">Trustin Lee</a>
*
* @version $Rev: 2121 $, $Date: 2010-02-02 09:38:07 +0900 (Tue, 02 Feb 2010) $
*/
public class FactorialClientHandler extends SimpleChannelUpstreamHandler {
private static final Logger logger = Logger.getLogger(
FactorialClientHandler.class.getName());
// Stateful properties
private int i = 1;
private int receivedMessages = 0;
private final int count;
final BlockingQueue<BigInteger> answer = new LinkedBlockingQueue<BigInteger>();
public FactorialClientHandler(int count) {
this.count = count;
}
public BigInteger getFactorial() {
boolean interrupted = false;
for (;;) {
try {
BigInteger factorial = answer.take();
if (interrupted) {
Thread.currentThread().interrupt();
}
return factorial;
} catch (InterruptedException e) {
interrupted = true;
}
}
}
@Override
public void handleUpstream(
ChannelHandlerContext ctx, ChannelEvent e) throws Exception {
if (e instanceof ChannelStateEvent) {
logger.info(e.toString());
}
super.handleUpstream(ctx, e);
}
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
sendNumbers(e);
}
@Override
public void channelInterestChanged(ChannelHandlerContext ctx, ChannelStateEvent e) {
sendNumbers(e);
}
@Override
public void messageReceived(
ChannelHandlerContext ctx, final MessageEvent e) {
receivedMessages ++;
if (receivedMessages == count) {
// Offer the answer after closing the connection.
e.getChannel().close().addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) {
boolean offered = answer.offer((BigInteger) e.getMessage());
assert offered;
}
});
}
}
@Override
public void exceptionCaught(
ChannelHandlerContext ctx, ExceptionEvent e) {
logger.log(
Level.WARNING,
"Unexpected exception from downstream.",
e.getCause());
e.getChannel().close();
}
private void sendNumbers(ChannelStateEvent e) {
Channel channel = e.getChannel();
while (channel.isWritable()) {
if (i <= count) {
channel.write(Integer.valueOf(i));
i ++;
} else {
break;
}
}
}
}