Netty01--- Netty实现简单通信

付威

发布于 2020-02-17 11:43:45

4190

发布于 2020-02-17 11:43:45

文章被收录于专栏：老付的网络博客老付的网络博客

这个Demo的功能是客户端向服务端发送一个Hello Netty的消息，然后服务端又把消息返回给客户端

Server端

这些都是一些公共的代码，代码比较简单，服务端负责监听端口，Handler负责处理业务逻辑

public class ServerProcessor {
     public void process(){
          EventLoopGroup bossGroup = new NioEventLoopGroup();
          EventLoopGroup workGroup = new NioEventLoopGroup();
          ServerBootstrap bootStrap = new ServerBootstrap();
          ChannelFuture cf;
          bootStrap.group(bossGroup,workGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG, 1024)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                         @Override
                         public void initChannel(SocketChannel ch) throws Exception {
                              ChannelPipeline p = ch.pipeline();
                              p.addLast(new ServerMessageHandler());//server的handler
                         }
                    });

          try {
               cf =  bootStrap.bind(8099).sync();//监听8099端口
               System.out.println("8099:binded...");
               cf.channel().closeFuture().sync();
          } catch (InterruptedException e) {
               e.printStackTrace();
          }finally{
               bossGroup.shutdownGracefully();
               workGroup.shutdownGracefully();
          }
     }

     public static void main(String[] args) {
          ServerProcessor serverProcessor = new ServerProcessor();
          serverProcessor.process();
     }
}

@ChannelHandler.Sharable
public class ServerMessageHandler extends ChannelInboundHandlerAdapter {

     @Override
     public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
          System.out.println("服务已启动,等待客户连接");
     }

     
     //接收客户端发送的消息
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
          ByteBuf in = (ByteBuf)msg;/*netty实现的缓冲区*/
          System.out.println("Server Accept:"+in.toString(CharsetUtil.UTF_8));
          ctx.write(in);
     }

     @Override
     public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
          ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)/*flush掉所有的数据*/
                    .addListener(ChannelFutureListener.CLOSE);/*当flush完成后，关闭连接*/
     }
}

Client端

public class ClientProcessor {

     public void process() {
          EventLoopGroup group =new NioEventLoopGroup();
          try {
               Bootstrap b = new Bootstrap();
               b.group(group)
                         .channel(NioSocketChannel.class)
                         .option(ChannelOption.TCP_NODELAY, true)
                         .handler(new ChannelInitializer<SocketChannel>(){
                         @Override
                         public void initChannel(SocketChannel ch) throws Exception {
                              ChannelPipeline p = ch.pipeline();
                              p.addLast(new ClientMessageHandler());

                         }
                         });

               ChannelFuture future = b.connect("127.0.0.1", 8099).sync();//连接端口

               future.channel().closeFuture().sync();
          } catch (InterruptedException e) {
               e.printStackTrace();
          } finally {
               group.shutdownGracefully();
          }

     }

     public static void main(String[] args) {
          ClientProcessor clientProcessor = new ClientProcessor();
          clientProcessor.process();
     }
}

public class ClientMessageHandler extends SimpleChannelInboundHandler<ByteBuf> {

     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
          ctx.channel().writeAndFlush(Unpooled.copiedBuffer("Hello Netty", CharsetUtil.UTF_8));
          ctx.fireChannelActive();
     }


     @Override
     protected void channelRead0(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf) throws Exception {
          System.out.println("NettyClient accetp:" + byteBuf.toString(CharsetUtil.UTF_8));
     }

     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
          cause.printStackTrace();
          ctx.close();
     }

}

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