使用JAVA操作netty框架

Netty简介：

 

Netty 是一个异步的，事件驱动的网络编程框架和工具，使用Netty 可以快速开发出可维护的，高性能、高扩展能力的协议服务及其客户端应用。

Netty原来属于JBoss开源社区，现在已经独立出来，新官网地址： http://netty.io/，最新版本为： 3.5.0.Beta1 and  3.4.6.Final。 Lisence为：ASL。

Netty Github地址：https://github.com/netty/netty/

 

如果您需要开发分布式应用，Netty可作为通信框架的一种选择。

之前使用过MINA框架，感觉效率非常好，使用长连接可以支持10万次以上的并发。 

今天尝试使用了Netty框架，感觉使用上也非常方便，具体效率问题，在接下来的博客会详细解读： 

NioServerSocketChannelFactory创建服务端的ServerSocketChannel，采用多线程执行非阻塞IO，和Mina的设计 

模式一样，都采用了Reactor模式。其中bossExecutor、workerExecutor是两个线程池，bossExecutor用来接收客户端连接，workerExecutor用来执行非阻塞的IO操作，主要是read，write。 

 package netty;

 import org.jboss.netty.bootstrap.ServerBootstrap;
 import org.jboss.netty.channel.ChannelFactory;
 import org.jboss.netty.channel.ChannelPipeline;
 import org.jboss.netty.channel.ChannelPipelineFactory;
 import org.jboss.netty.channel.Channels;
 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 java.net.InetSocketAddress;
 import java.util.concurrent.Executors;

 /**
  * Created by IntelliJ IDEA.
  * User: flychao88
  * Date: 12-6-6
  * Time: 上午10:14
  * To change this template use File | Settings | File Templates.
  */
 public class DiscardServer {
     public static void main(String[] args) throws Exception {
         ChannelFactory factory = new NioServerSocketChannelFactory(
             Executors.newCachedThreadPool(),
             Executors.newCachedThreadPool());
         ServerBootstrap bootstrap = new ServerBootstrap (factory);
         bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
             public ChannelPipeline getPipeline() {
                  ChannelPipeline pipeline = Channels.pipeline();
                 pipeline.addLast("encode",new StringEncoder());
                 pipeline.addLast("decode",new StringDecoder());
                 pipeline.addLast("handler",new DiscardServerHandler());
                 return pipeline;
             }
         });
         bootstrap.setOption("child.tcpNoDelay", true);
         bootstrap.setOption("child.keepAlive", true);
         bootstrap.bind(new InetSocketAddress(8080));
     }
 }

 package netty;

 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
 import org.jboss.netty.channel.*;

 /**
  * Created by IntelliJ IDEA.
  * User: flychao88
  * Date: 12-6-6
  * Time: 上午10:10
  * To change this template use File | Settings | File Templates.
  */
 public class DiscardServerHandler extends SimpleChannelUpstreamHandler  {
     @Override
     public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
        System.out.println("服务器接收1："+e.getMessage());
     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
         e.getCause().printStackTrace();
         Channel ch = e.getChannel();
         ch.close();
     }
 }

 package netty;

 import org.jboss.netty.bootstrap.ClientBootstrap;
 import org.jboss.netty.channel.ChannelFactory;
 import org.jboss.netty.channel.ChannelPipeline;
 import org.jboss.netty.channel.ChannelPipelineFactory;
 import org.jboss.netty.channel.Channels;
 import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
 import org.jboss.netty.handler.codec.string.StringDecoder;
 import org.jboss.netty.handler.codec.string.StringEncoder;

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

 /**
  * Created by IntelliJ IDEA.
  * User: flychao88
  * Date: 12-6-6
  * Time: 上午10:21
  * To change this template use File | Settings | File Templates.
  */
 public class TimeClient {
     public static void main(String[] args) throws Exception {

         ChannelFactory factory = new NioClientSocketChannelFactory(
             Executors.newCachedThreadPool(),
             Executors.newCachedThreadPool());
         ClientBootstrap bootstrap = new ClientBootstrap(factory);
         bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
             public ChannelPipeline getPipeline() {
                 ChannelPipeline pipeline = Channels.pipeline();
                 pipeline.addLast("encode",new StringEncoder());
                 pipeline.addLast("decode",new StringDecoder());
                 pipeline.addLast("handler",new TimeClientHandler());
                 return pipeline;
             }
         });
         bootstrap.setOption("tcpNoDelay" , true);
         bootstrap.setOption("keepAlive", true);
         bootstrap.connect (new InetSocketAddress("127.0.0.1", 8080));
     }
 }

 package netty;

 /**
  * Created by IntelliJ IDEA.
  * User: flychao88
  * Date: 12-6-6
  * Time: 上午10:22
  * To change this template use File | Settings | File Templates.
  */
 import org.jboss.netty.buffer.ChannelBuffer;
 import org.jboss.netty.buffer.ChannelBuffers;
 import org.jboss.netty.channel.*;

 import java.util.Date;


 public class TimeClientHandler extends SimpleChannelUpstreamHandler  {
     @Override
     public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
         e.getChannel().write("abcd");
     }

     @Override
     public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
         e.getChannel().close();
     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
         e.getCause().printStackTrace();
         e.getChannel().close();
     }
 }