maven netty5服務端與客戶端的構建

maven版本依賴

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>5.0.0.Alpha2</version>
</dependency>

服務端代碼的編寫順序。

1. 得到 ServerBootstrap的對象，用來監聽客戶端
   

   ServerBootstrap serverBootstrap = new ServerBootstrap();  

2. 創建兩個線程池
   

   EventLoopGroup boss = new NioEventLoopGroup();  
   EventLoopGroup worker = new NioEventLoopGroup();  
   

   boss用來對端口的監聽，worker對數據進行處理

3. 設置工廠
   

   serverBootstrap.group(boss, worker);  
   serverBootstrap.channel(NioServerSocketChannel.class);  

4. 設置，可以理解為netty3中的管道
   

   serverBootstrap.childHandler(new ChannelInitializer<Channel>() {
   
   				@Override
   				protected void initChannel(Channel channel) throws Exception {
   					/**
   					 * 將“上傳下載”數據裝飾成String類型
   					 */
   					channel.pipeline().addLast(new StringDecoder());
   					channel.pipeline().addLast(new StringEncoder());
   					// 要處理的Handler
   					channel.pipeline().addLast(new ServerHandler2());
   				}
   			});

5. 設置TCP參數
   

   serverBootstrap.option(ChannelOption.SO_BACKLOG, 2048);// serverSocketchannel的設置，鏈接緩沖池的大小
   serverBootstrap.childOption(ChannelOption.SO_KEEPALIVE, true);// socketchannel的設置,維持鏈接的活躍，清除死鏈接
   serverBootstrap.childOption(ChannelOption.TCP_NODELAY, true);// socketchannel的設置,關閉延遲發送

6. 綁定端口
   

   ChannelFuture future = serverBootstrap.bind(new InetSocketAddress(9090));

7. (等待)關閉客戶端
   

   Channel channel = future.channel();
   channel.closeFuture().sync();

   完整代碼如下:
   服務端:

   package com.netty5.server;
   
   import java.net.InetSocketAddress;
   
   import io.netty.bootstrap.ServerBootstrap;
   import io.netty.channel.Channel;
   import io.netty.channel.ChannelFuture;
   import io.netty.channel.ChannelHandlerContext;
   import io.netty.channel.ChannelInitializer;
   import io.netty.channel.ChannelOption;
   import io.netty.channel.EventLoopGroup;
   import io.netty.channel.SimpleChannelInboundHandler;
   import io.netty.channel.nio.NioEventLoopGroup;
   import io.netty.channel.socket.nio.NioServerSocketChannel;
   import io.netty.handler.codec.string.StringDecoder;
   import io.netty.handler.codec.string.StringEncoder;
   
   /**
    * @author Chalmers 2016年2月20日 下午7:52:49
    */
   public class NettyServer2 {
   
       public static void main(String[] args) {
           // 得到ServerBootstrap對象
           ServerBootstrap serverBootstrap = new ServerBootstrap();
   
           // 創建線程池
           EventLoopGroup boss = new NioEventLoopGroup();
           EventLoopGroup worker = new NioEventLoopGroup();
   
           try {
               // 類似於Netty3中的工廠
               serverBootstrap.group(boss, worker);
               serverBootstrap.channel(NioServerSocketChannel.class);
   
               // 類似於Netty3中的管道
               serverBootstrap.childHandler(new ChannelInitializer<Channel>() {
   
                   @Override
                   protected void initChannel(Channel channel) throws Exception {
                       /**
                        * 將“上傳下載”數據裝飾成String類型
                        */
                       channel.pipeline().addLast(new StringDecoder());
                       channel.pipeline().addLast(new StringEncoder());
                       // 要處理的Handler
                       channel.pipeline().addLast(new ServerHandler2());
                   }
               });
   
               // 設置參數，TCP參數
               serverBootstrap.option(ChannelOption.SO_BACKLOG, 2048);// serverSocketchannel的設置，鏈接緩沖池的大小
               serverBootstrap.childOption(ChannelOption.SO_KEEPALIVE, true);// socketchannel的設置,維持鏈接的活躍，清除死鏈接
               serverBootstrap.childOption(ChannelOption.TCP_NODELAY, true);// socketchannel的設置,關閉延遲發送
   
               // 綁定端口，並且返回ChannelFuture對象
               ChannelFuture future = serverBootstrap.bind(new InetSocketAddress(
                       9090));
   
               System.out.println("啟動服務器...");
   
               // 等待客戶端的關閉
               Channel channel = future.channel();
               // 要記得是closeFuture()，作用是等待服務端的關閉
               channel.closeFuture().sync();
               // 該條語句不會輸出，原因:上面沒有關閉...
               // System.out.println("客戶端已經關閉...");
           } catch (Exception e) {
               e.printStackTrace();
           } finally {
               boss.shutdownGracefully();
               worker.shutdownGracefully();
           }
       }
   }
   
   class ServerHandler2 extends SimpleChannelInboundHandler<String> {
   
       @Override
       protected void messageReceived(ChannelHandlerContext arg0, String arg1)
               throws Exception {
           // 輸出接收到的數據
           System.out.println(arg1);
   
           // 向客戶端發送數據
           arg0.channel().writeAndFlush("hi");
       }
   
       /**
        * 
        */
       @Override
       public void channelActive(ChannelHandlerContext ctx) throws Exception {
           super.channelActive(ctx);
           System.out.println("channelActive");
       }
   
       @Override
       public void channelInactive(ChannelHandlerContext ctx) throws Exception {
           super.channelInactive(ctx);
           System.out.println("channelInactive");
       }
   }

   客戶端:

   package com.netty.client;
   
   import java.io.BufferedReader;
   import java.io.IOException;
   import java.io.InputStreamReader;
   
   import io.netty.bootstrap.Bootstrap;
   import io.netty.channel.Channel;
   import io.netty.channel.ChannelFuture;
   import io.netty.channel.ChannelHandlerContext;
   import io.netty.channel.ChannelInitializer;
   import io.netty.channel.EventLoopGroup;
   import io.netty.channel.SimpleChannelInboundHandler;
   import io.netty.channel.nio.NioEventLoopGroup;
   import io.netty.channel.socket.nio.NioSocketChannel;
   import io.netty.handler.codec.string.StringDecoder;
   import io.netty.handler.codec.string.StringEncoder;
   
   /**
    * @author Chalmers 2016年2月20日 下午8:31:25
    */
   public class Client {
   
       public static void main(String[] args) {
           Bootstrap bootstrap = new Bootstrap();
   
           EventLoopGroup worker = new NioEventLoopGroup();
   
           bootstrap.channel(NioSocketChannel.class);
           bootstrap.group(worker);
   
           bootstrap.handler(new ChannelInitializer<Channel>() {
   
               @Override
               protected void initChannel(Channel channel) throws Exception {
                   channel.pipeline().addLast(new StringEncoder());
                   channel.pipeline().addLast(new StringDecoder());
                   channel.pipeline().addLast(new ClientHandler());
               }
           });
   
           ChannelFuture future = bootstrap.connect("127.0.0.1", 9090);
   
           BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
           while (true) {
               System.out.print("輸入: ");
               try {
                   String line = br.readLine();
                   future.channel().writeAndFlush(line);
               } catch (IOException e) {
                   e.printStackTrace();
               }
           }
       }
   }
   
   class ClientHandler extends SimpleChannelInboundHandler<String> {
   
       @Override
       protected void messageReceived(ChannelHandlerContext arg0, String arg1)
               throws Exception {
           System.out.println("收到服務端發送的消息..." + arg1);
       }
   
       @Override
       public void channelActive(ChannelHandlerContext ctx) throws Exception {
           // TODO Auto-generated method stub
           super.channelActive(ctx);
       }
   
       @Override
       public void channelInactive(ChannelHandlerContext ctx) throws Exception {
           // TODO Auto-generated method stub
           super.channelInactive(ctx);
       }
       
       
   }

   因為netty5與netty3的差別挺大，所以注意區分開。

   http://moonmonster.iteye.com/blog/2278672

    

   當然，因為本人水平有限，所以更詳細的解釋可見

   netty權威指南作者的博客

   http://www.infoq.com/cn/articles/netty-server-create