Netty使用实例

Netty使用实例

贴上两个自己写好的Netty使用实例，以便备注，以下两个例子基于netty-3.5.7.Final.jar用Junit进行测试

Netty 的详细介绍：请点这里
Netty 的下载地址：请点这里

相关阅读：Netty源码学习笔记

第一个例子：简单的发送字符串，接收字符串“Hello, World”

package com.wujintao.netty;

import java.net.InetSocketAddress;
import java.util.concurrent.Executors;

import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
import org.jboss.netty.handler.codec.string.StringDecoder;
import org.jboss.netty.handler.codec.string.StringEncoder;
import org.junit.Test;

class HelloWorldServerHandler extends SimpleChannelHandler {
 public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e)
   throws Exception {
  e.getChannel().write("Hello, World");
 }

 public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
  System.out.println("Unexpected exception from downstream."
    + e.getCause());
  e.getChannel().close();
 }
}

class HelloWorldClientHandler extends SimpleChannelHandler {

 public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
  String message = (String) e.getMessage();
  System.out.println(message);
  e.getChannel().close();
 }

 public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
  System.out.println("Unexpected exception from downstream."
    + e.getCause());
  e.getChannel().close();
 }
}

/**
 * Netty VS MinaNetty基于Pipeline处理，Mina基于Filter过滤
 * Netty的事件驱动模型具有更好的扩展性和易用性
 * Https，SSL，PB，RSTP，Text &Binary等协议支持
 * Netty中UDP传输有更好的支持官方测试Netty比Mina性能更好
 * @author Administrator
 *
 */
public class TestCase {

 public void testServer() {
  //初始化channel的辅助类，为具体子类提供公共数据结构
  ServerBootstrap bootstrap = new ServerBootstrap(
    new NioServerSocketChannelFactory(
      Executors.newCachedThreadPool(),
      Executors.newCachedThreadPool()));
  bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
   public ChannelPipeline getPipeline() {
    ChannelPipeline pipeline = Channels.pipeline();
    pipeline.addLast("decoder", new StringDecoder());
    pipeline.addLast("encoder", new StringEncoder());
    pipeline.addLast("handler", new HelloWorldServerHandler());
    return pipeline;
   }
  });
  //创建服务器端channel的辅助类,接收connection请求
  bootstrap.bind(new InetSocketAddress(8080));
 }
 
 
 
 public void testClient() {
  //创建客户端channel的辅助类,发起connection请求
  ClientBootstrap bootstrap = new ClientBootstrap(
    new NioClientSocketChannelFactory(
      Executors.newCachedThreadPool(),
      Executors.newCachedThreadPool()));
  //It means one same HelloWorldClientHandler instance is going to handle multiple Channels and consequently the data will be corrupted.
  //基于上面这个描述，必须用到ChannelPipelineFactory每次创建一个pipeline
  bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
   public ChannelPipeline getPipeline() {
    ChannelPipeline pipeline =  Channels.pipeline();
    pipeline.addLast("decoder", new StringDecoder());
    pipeline.addLast("encoder", new StringEncoder());
    pipeline.addLast("handler", new HelloWorldClientHandler());
    return pipeline;
   }
  });
  //创建无连接传输channel的辅助类(UDP),包括client和server
  ChannelFuture future = bootstrap.connect(new InetSocketAddress(
    "localhost", 8080));
  future.getChannel().getCloseFuture().awaitUninterruptibly();
  bootstrap.releaseExternalResources();
 }
 
 
 @Test
 public void testNetty(){
  testServer();
  testClient();
 }

}

第二个例子见下一页：