服务端demo

服务端启动Demo

        
        // 两个线程池
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        // 服务端handler
        final EchoServerHandler serverHandler = new EchoServerHandler();
        try {
            // 服务端 引导器
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .option(ChannelOption.SO_BACKLOG, 100)
             .handler(new LoggingHandler(LogLevel.INFO))
             .childHandler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ChannelPipeline p = ch.pipeline();
                     if (sslCtx != null) {
                         p.addLast(sslCtx.newHandler(ch.alloc()));
                     }
                     //p.addLast(new LoggingHandler(LogLevel.INFO));
                     p.addLast(serverHandler);
                 }
             });

            // Start the server.
            // 启动 服务器
            ChannelFuture f = b.bind(PORT).sync();

            // Wait until the server socket is closed.
            f.channel().closeFuture().sync();
        } finally {
            // Shut down all event loops to terminate all threads.
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }

服务端handler

@Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter {

    // netty 收到读事件会激活这个方法
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        System.err.println("收到一条消息....");
        ctx.write(msg);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        // Close the connection when an exception is raised.
        cause.printStackTrace();
        ctx.close();
    }
}

启动 Netty 客户端

// Configure the client.
        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();
                     if (sslCtx != null) {
                         p.addLast(sslCtx.newHandler(ch.alloc(), HOST, PORT));
                     }
                     //p.addLast(new LoggingHandler(LogLevel.INFO));
                     p.addLast(new EchoClientHandler());
                 }
             });

            // Start the client.
            ChannelFuture f = b.connect(HOST, PORT).sync();

            // Wait until the connection is closed.
            f.channel().closeFuture().sync();
        } finally {
            // Shut down the event loop to terminate all threads.
            group.shutdownGracefully();
        }

客户端 handler

public class EchoClientHandler extends ChannelInboundHandlerAdapter {

    private final ByteBuf firstMessage;

    /**
     * Creates a client-side handler.
     */
    public EchoClientHandler() {
        firstMessage = Unpooled.buffer(EchoClient.SIZE);
        for (int i = 0; i < firstMessage.capacity(); i++) {
            firstMessage.writeByte((byte) i);
        }
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(firstMessage);
    }

    /**
     * 可见 客户端合服务端互刷消息...
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        System.err.println("客户端也收到了消息");
        ctx.write(msg);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        // Close the connection when an exception is raised.
        cause.printStackTrace();
        ctx.close();
    }
}