java技术--Netty客户端实现(03)

1.客户端代码示例

public class Client {
  static final String HOST = System.getProperty("host", "127.0.0.1");
  static final int PORT = Integer.parseInt(System.getProperty("port", "8081"));
  static final int SIZE = Integer.parseInt(System.getProperty("size", "256"));
  public static void main(String[] args) throws Exception {sendMessage("你好:Netty");}
  public static void sendMessage(String content) throws InterruptedException{
     // 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();
                p.addLast("decoder", new StringDecoder());
                p.addLast("encoder", new StringEncoder());
                p.addLast(new ClientHandler());}});
            ChannelFuture future = b.connect(HOST, PORT).sync();
            future.channel().writeAndFlush(content);
            future.channel().closeFuture().sync();
        } finally {group.shutdownGracefully();}}}

2.创建ClientChannelInitializer类示例:

public class ClientChannelInitializer extends ChannelInitializer<SocketChannel> {
    protected void initChannel(SocketChannel channel) throws Exception {
        ChannelPipeline p = channel.pipeline();
        p.addLast("decoder", new StringDecoder(CharsetUtil.UTF_8));
        p.addLast("encoder", new StringEncoder(CharsetUtil.UTF_8));
        p.addLast(new ClientHandler());}}

3.创建ClientHandler类示例

public class ClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        System.out.println("ClientHandler Active");}
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        System.out.println("--------");
        System.out.println("ClientHandler read Message:"+msg);}
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {cause.printStackTrace();ctx.close();}}

4.参考文档:https://www.cnblogs.com/Yintianhao/p/10181245.html