Netty入门

Netty

1. ChannelEvent 某一事件
2. ChannelPipeline 管道、传输途径。控制ChannelEvent事件传递和分发
3. ChannelHandler 站点处理业务逻辑
4. Channel 协调总部门
5. EventLoopGroup 线程池调度处理各种数据

DEMO

Server

public class DemoServer {
  private static final int port = 8888;
  public static void main(String[] args) throws Exception {
    EventLoopGroup mainGroup = new NioEventLoopGroup();
    EventLoopGroup workGroup = new NioEventLoopGroup();
    try{
      ServerBootstrap boot = new ServerBootStrap();
      //主从Reactor多线程模型
      boot.group(mainGroup, workGroup);
      //NIO传输
      boot.channel(NioServerSocketChannel.class);
      //handler处理流程
      boot.childHandler(new DemoServerInitializer());
      ChannelFuture f = boot.bind(port).sync();
      f.channel().closeFuture().sync();
    }finally{
      mainGroup.shutdownGracefully();
      workGroup.shutdownGracefully();
    }
  }
}

public class DemoServerInitializer extends ChannelInitializer<SocketChannel> {
  @Override
  protected void initChannel(SocketChannel socketChannel) throws Exception {
    //获取pipeline
    ChannelPipeline pipeline = socketChannel.pipeline);
    //解码器
    pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8000,Delimiters.lineDelimiter()));
    pipeline.addLast("decoder", new StringDecoder());
    pipeline.addLast("encode", new StringEncode());

    pipeline.addLast("handler", new DemoHandler());

  }
}

public classDemoHandler extends SimpleChannelInboundHandler<String> {
  @Override
  portected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
    System.out.println(ctx.channel().remoteAddress() + "Msg:" + msg);

    ctx.writeAndFlush("succ get msg \n");
  }

  //建立链接时触发
  @Override
  public void channelActive(ChannelHandlerContext ctx) throws Exception {
    ctx.write("welcome to netty \n");
    ctx.flush();

    super.channelActive(ctx);
  }
}

client端

public class DemoClient{
    public static final String host = "127.0.0.1";
    public static final String port = 8888;

    public staic void main(String[] args) throws Exception {
      EventLoopGroup group = new NioEventLoopGroup();
      try{
        BootStrap boot = new BootStrap();
        boot.group(group).channel(NioSocketChannel.class).handler(new DemoClientInitializer());
        Channel channel = b.connect(host, port).sync().channel();

        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for(;;) {
          String line = in.readLine();
          if(line == null) {
            continue;
          }
          channel.writeAndFulsh(line + "\r\n");
        }
      }finally {
        group.shutdownGracefully();
      }
    }
  }

public class DemoClientInitializer extends ChannelInitializer<SocketChannel> {
  @Override
  protected void initChannel(SocketChannel socketChannel) throws Exception {
    ChannelPipeline pipeline = socketChannel.pipeline);
    //解码器
    pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8000,Delimiters.lineDelimiter()));
    pipeline.addLast("decoder", new StringDecoder());
    pipeline.addLast("encode", new StringEncode());

    pipeline.addLast("handler", new DemoClientHandler());
  }
}

public class DemoClientHandler extends SimpleChannelInboundHanlder<String> {
    //接收服务端的信息
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, String s) throws Exception {
        System.out.println("Server msg : " + s);
    }

    //连接成功时触发
    @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("Client connect ");
        super.channelActive(ctx);
     }

    //关闭时触发
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("Client close ");
        super.channelInactive(ctx);
    }
}