ProtoBufClient

public class ProtoBufClient {
    public void connect(int port, String host) throws Exception {
        // 配置客户端NIO线程组
        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 {
                            /*加一个消息长度，由netty自动计算 粘包半包问题*/
                            ch.pipeline().addLast(new ProtobufVarint32LengthFieldPrepender());
                            /*负责编码,序列化*/
                            ch.pipeline().addLast(new ProtobufEncoder());
                            ch.pipeline().addLast(new ProtoBufClientHandler());
                        }
                    });
            ChannelFuture f = b.connect(host, port).sync();
            f.channel().closeFuture().sync();
        } finally {
            // 优雅退出，释放NIO线程组
            group.shutdownGracefully();
        }
    }
    public static void main(String[] args) throws Exception {
        int port = 8080;
        new ProtoBufClient().connect(port, "127.0.0.1");
    }
}