Netty|02 easy example

        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-all</artifactId>
            <version>4.1.15.Final</version>
        </dependency>

public class NettyServer {
    public static void main(String[] args) throws InterruptedException {
//        创建线程池 接受连接
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
//        创建线程池，处理io
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
//        创建服务器端启动助手
        ServerBootstrap serverBootstrap = new ServerBootstrap();
//        配置启动助手
        serverBootstrap.group(bossGroup, workGroup)//设置两个线程池
                .channel(NioServerSocketChannel.class)//使用作为服务器端的通道实现
                .option(ChannelOption.SO_BACKLOG, 128)//设置线程队列中等待连接的个数
                .childOption(ChannelOption.SO_KEEPALIVE, true)//保持活动连接状态
                .childHandler(new ChannelInitializer<SocketChannel>() { //创建通道初始化的对象
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new NettyServerHandler());
                    }
                });
        System.out.println("----------------server is ready--------------------");
        ChannelFuture cf = serverBootstrap.bind(9999).sync();//绑定端口，异步
        System.out.println("----------------server is starting--------------------");
//        关闭通道、关闭通道组
        cf.channel().closeFuture().sync();
        bossGroup.shutdownGracefully();
        workGroup.shutdownGracefully();

    }
}

/**
 * 服务器业务处理块
 */
public class NettyServerHandler extends ChannelInboundHandlerAdapter {

    /**
     * 读取数据事件
     * @param ctx
     * @param msg
     * @throws Exception
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        System.out.println("server:"+ctx);
        ByteBuf buf = (ByteBuf)msg;
        System.out.println("客户端发来消息:"+buf.toString(CharsetUtil.UTF_8));

    }

    /**
     *数据读取完毕
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(Unpooled.copiedBuffer("就是没钱啦！",CharsetUtil.UTF_8));
    }

    /**
     * 异常发生
     * @param ctx
     * @param cause
     * @throws Exception
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
    }
}

public class NettyClient {
    public static void main(String[] args) throws InterruptedException {

//        创建一个线程组
        NioEventLoopGroup group = new NioEventLoopGroup();
        //2. 创建客户端的启动助手，完成相关配置
        Bootstrap bootstrap = new Bootstrap();
        bootstrap.group(group)//3. 设置线程组
                .channel(NioSocketChannel.class)//4. 设置客户端通道的实现类
                .handler(new ChannelInitializer<SocketChannel>() {//5. 创建一个通道初始化对象
                    @Override
                    protected void initChannel(SocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new NettyClientHandler());//6.往Pipeline链中添加自定义的handler
                    }
                });
        System.out.println("......Client is  ready......");

        //7.启动客户端去连接服务器端  connect方法是异步的   sync方法是同步阻塞的
        ChannelFuture cf = bootstrap.connect("127.0.0.1", 9999).sync();

//        关闭连接
        cf.channel().closeFuture().sync();

    }
}

public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    /**
     * 通道就绪事件
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("client:"+ctx);
        ctx.writeAndFlush(Unpooled.copiedBuffer("老板还钱吧！", CharsetUtil.UTF_8));
    }

    /**
     * 读取数据
     * @param ctx
     * @param msg
     * @throws Exception
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf buf = (ByteBuf)msg;
        System.out.println("服务器发来消息："+buf.toString(CharsetUtil.UTF_8));
    }
}