使用Netty框架实现一个简单的CS结构的网络程序处理tcp半包问题粘包、拆包完整代码

以下是使用Netty框架实现一个简单的C/S结构的网络程序处理tcp半包问题的完整代码：

服务端代码：

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.LengthFieldPrepender;

public class Server {

    public static void main(String[] args) throws Exception {
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new LengthFieldBasedFrameDecoder(65535, 0, 2, 0, 2));
                            pipeline.addLast(new LengthFieldPrepender(2));
                            pipeline.addLast(new SimpleChannelInboundHandler<ByteBuf>() {
                                @Override
                                protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) throws Exception {
                                    byte[] bytes = new byte[msg.readableBytes()];
                                    msg.readBytes(bytes);
                                    String message = new String(bytes, "UTF-8");
                                    System.out.println("Received message from client: " + message);
                                }
                            });
                        }
                    });
            ChannelFuture future = bootstrap.bind(8888).sync();
            System.out.println("Server started on port 8888...");
            future.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

客户端代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class Client {

    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("localhost", 8888);
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);

        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        while (true) {
            System.out.print("Enter message to send to server: ");
            String message = reader.readLine();
            out.println(message);
            String response = in.readLine();
            System.out.println("Received response from server: " + response);
        }
    }
}

在这个示例中，服务端使用了LengthFieldBasedFrameDecoder和LengthFieldPrepender来解决tcp半包问题。LengthFieldBasedFrameDecoder会自动处理粘包和拆包，并将每个完整的消息分配给SimpleChannelInboundHandler处理。客户端通过Socket连接到服务端，使用PrintWriter将消息发送给服务端，然后通过BufferedReader读取服务端的响应