java netty 发送消息

以下是使用Java Netty发送消息的示例代码：

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

public class NettyClient {
    public static void main(String[] args) throws Exception {
        String host = "localhost";
        int port = 8080;

        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(workerGroup)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.SO_KEEPALIVE, true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new NettyClientHandler());
                        }
                    });

            ChannelFuture future = bootstrap.connect(host, port).sync();
            Channel channel = future.channel();

            // 发送消息
            String message = "Hello, Netty!";
            channel.writeAndFlush(message);

            // 关闭连接
            channel.closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }
}

请注意，上述代码中的`NettyClientHandler`是一个自定义的处理器，用于处理接收到的消息。你可以根据自己的需求来实现该处理器。