netty websocket client

您好！Netty 是一个基于 Java 的网络编程框架，可以用来构建高性能的网络应用程序。下面是一个简单的 Netty WebSocket 客户端示例代码：

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
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.nio.NioSocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpRequest;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpRequestEncoder;
import io.netty.handler.codec.http.HttpResponseDecoder;
import io.netty.handler.codec.http.websocketx.*;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;

import java.net.URI;

public class NettyWebSocketClient {

    public static void main(String[] args) throws Exception {
        URI uri = new URI("ws://localhost:8080/ws"); // WebSocket 服务器地址

        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap()
                    .group(group)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000) // 连接超时时间
                    .handler(new ChannelInitializer<Channel>() {
                        @Override
                        protected void initChannel(Channel ch) throws Exception {
                            ch.pipeline().addLast(
                                    new HttpClientCodec(),
                                    new HttpObjectAggregator(8192),
                                    new WebSocketClientProtocolHandler(
                                            WebSocketClientHandshakerFactory.newHandshaker(
                                                    uri, WebSocketVersion.V13, null, true, null),
                                            true),
                                    new WebSocketClientHandler());
                        }
                    });

            Channel channel = bootstrap.connect(uri.getHost(), uri.getPort()).sync().channel();
            channel.closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }

    private static class WebSocketClientHandler extends SimpleChannelInboundHandler<WebSocketFrame> {
        @Override
        protected void channelRead0(ChannelHandlerContext ctx, WebSocketFrame frame) throws Exception {
            // 处理 WebSocket 服务器返回的消息
            if (frame instanceof TextWebSocketFrame) {
                TextWebSocketFrame textFrame = (TextWebSocketFrame) frame;
                System.out.println("Received message: " + textFrame.text());
            } else if (frame instanceof CloseWebSocketFrame) {
                System.out.println("WebSocket client received closing");
                ctx.close();
            }
        }

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

您可以根据实际情况修改代码中的 WebSocket 服务器地址，然后运行这段代码即可实现 Netty WebSocket 客户端的功能。希望能对您有所帮助！如有任何问题，请随时提问。