Netty服务器客户端服务端完整一次交互

上次的Netty服务器只实现了最基本的功能，让客户端向服务端成功地发送了信息。这次的代码成功实现了S和C的双端交互，在此记录一下。

HttpServer.java

public class HttpServer {
    private static final int PORT = 8080;
    public static void main(String[] args) throws Exception{
        //创建两个线程组 bossGroup、workerGroup
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            //创建服务端的启动对象，设置参数
            ServerBootstrap bootstrap = new ServerBootstrap();
            //设置两个线程组boosGroup和workerGroup
            bootstrap.group(bossGroup, workerGroup)
                    //设置服务端通道实现类型
                    .channel(NioServerSocketChannel.class)
                    //设置线程队列得到连接个数
                    .option(ChannelOption.SO_BACKLOG, 128)
                    //设置保持活动连接状态
                    .childOption(ChannelOption.SO_KEEPALIVE, true)
                    //使用匿名内部类的形式初始化通道对象
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {
                            //给pipeline管道设置处理器
                            socketChannel.pipeline().addLast(new HttpServerHandler());
                        }
                    });//给workerGroup的EventLoop对应的管道设置处理器
            log.info("服务端已经准备就绪...");
            //绑定端口号，启动服务端
            ChannelFuture channelFuture = bootstrap.bind(PORT).sync();
            //对关闭通道进行监听
            channelFuture.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

HttpServerHandler.java

@Slf4j
public class HttpServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        //获取客户端发送过来的消息
        ByteBuf byteBuf = (ByteBuf) msg;
        log.debug("收到客户端" + ctx.channel().remoteAddress() + "发送的消息：" + byteBuf.toString(CharsetUtil.UTF_8));
    }
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        //发送消息给客户端
        ctx.writeAndFlush(Unpooled.copiedBuffer("服务端已收到消息,并向客户端发送了这条消息.", CharsetUtil.UTF_8));
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //发生异常，关闭通道
        ctx.close();
    }
}

HttpClient.java

public class HttpClient {
    public static void main(String[] args) throws Exception {
        NioEventLoopGroup eventExecutors = new NioEventLoopGroup();
        try {
            //创建bootstrap对象，配置参数
            Bootstrap bootstrap = new Bootstrap();
            //设置线程组
            bootstrap.group(eventExecutors)
                    //设置客户端的通道实现类型    
                    .channel(NioSocketChannel.class)
                    //使用匿名内部类初始化通道
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            //添加客户端通道的处理器
                            ch.pipeline().addLast(new HttpClientHandler());
                        }
                    });
            log.info("客户端准备就绪");
            //连接服务端
            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1", 8080).sync();
            //对通道关闭进行监听
            channelFuture.channel().closeFuture().sync();
        } finally {
            //关闭线程组
            eventExecutors.shutdownGracefully();
        }
    }
}

HttpClientHandler.java

@Slf4j
public class HttpClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        //发送消息到服务端
        ctx.writeAndFlush(Unpooled.copiedBuffer("客户端发了个消息.", CharsetUtil.UTF_8));
    }
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        //接收服务端发送过来的消息
        ByteBuf byteBuf = (ByteBuf) msg;
        log.debug("收到服务端" + ctx.channel().remoteAddress() + "的消息：" + byteBuf.toString(CharsetUtil.UTF_8));
    }
}