从IO模型到Netty笔记（六）

入站从pipeline的头部开始执行

出站从pipeline的尾部开始执行

服务端代码

public class NettyServer {
    public static void main(String[] args) {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup(1);
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {
                            ChannelPipeline pipeline = socketChannel.pipeline();
                            pipeline.addLast(new MyEncode());
                            pipeline.addLast(new MyDecode());
                            pipeline.addLast(new MyServerHandler());
                        }
                    });

            ChannelFuture channelFuture = serverBootstrap.bind(6668).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }
}

public class MyServerHandler extends SimpleChannelInboundHandler {
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, Long aLong) throws Exception {
        System.out.println("服务端接收到消息"+aLong);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
//        System.out.println("服务端发送数据");
//        ctx.writeAndFlush(98765L);
    }

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

客户端代码

public class NettyClient {
    public static void main(String[] args) {
        NioEventLoopGroup loopGroup = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(loopGroup)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer() {
                        @Override
                        protected void initChannel(SocketChannel socketChannel) throws Exception {
                            ChannelPipeline pipeline = socketChannel.pipeline();
                            pipeline.addLast(new MyEncode());
                            pipeline.addLast(new MyDecode());
                            pipeline.addLast(new MyClientHanlder());
                        }
                    });
            ChannelFuture channelFuture = bootstrap.connect("localhost", 6668).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            loopGroup.shutdownGracefully();
        }
    }
}

public class MyClientHanlder extends SimpleChannelInboundHandler {
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, Long aLong) throws Exception {
//        System.out.println("客户端接收消息"+aLong);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("发送信息");
//        ctx.writeAndFlush(1234L); // long 是8字节 解码一次即可
        // "abcdabcdabcdabcd" 是十六字节 所以解码两次
        ctx.writeAndFlush(Unpooled.copiedBuffer("abcdabcdabcdabcd", CharsetUtil.UTF_8));
    }

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

编解码

public class MyEncode extends MessageToByteEncoder {
    @Override
    protected void encode(ChannelHandlerContext channelHandlerContext, Long aLong, ByteBuf byteBuf) throws Exception {
        System.out.println("编码---------------------");
        byteBuf.writeLong(aLong);
    }
}

public class MyDecode extends ByteToMessageDecoder {
    @Override
    protected void decode(ChannelHandlerContext channelHandlerContext, ByteBuf byteBuf, List