客户端无法从服务器接收 UDP 数据报

Posted 2023-02-24

【中文标题】客户端无法从服务器接收 UDP 数据报

【英文标题】：Client can't receive UDP datagram from the server

【发布时间】：2014-04-02 23:13:31

【问题描述】：

但是，我可以将 UDP 数据报从我的客户端发送到我的服务器并接收它 我无法将数据报从我的服务器发送回客户端。

什么都没有发生。 我所看到的是： 服务器端的“Hello Server”，但我没有看到： 客户端的“Hello Client”。

    final int PACKETSIZE = 100;

//CLIENT
        byte[] newData = "Hello Server".getBytes();
        DatagramPacket newPacket = new DatagramPacket(newData, newData.length, packet.getAddress(), packet.getPort());

        // Send it
        socket.send(newPacket);

        // Set a receive timeout, 2000 milliseconds
        socket.setSoTimeout(2000);

        // Prepare the packet for receive
        packet.setData(new byte[PACKETSIZE]);

        // Wait for a response from the server
        socket.receive(packet);

        // Print the response
        System.out.println("RECEIVED MESSAGE FROM SERVER: " + new String(packet.getData()));

//SERVER
        int port = Integer.parseInt("1024");
        socket = new DatagramSocket(port);

        System.out.println("SERVER STARTED ON UDP PORT: " + port);


        while (true) 
            // Create a packet
            packet = new DatagramPacket(new byte[PACKETSIZE], PACKETSIZE);

            // Receive a packet (blocking)
            socket.receive(packet);

            // Print the packet sent from the client
            System.out.println(packet.getAddress() + " " + packet.getPort() + ": " + new String(packet.getData()));
            // Create a new packet to send back to the client
            byte[] newData = "Hello Client".getBytes();
            DatagramPacket newPacket = new DatagramPacket(newData, newData.length, packet.getAddress(), packet.getPort());
            // Return the packet to the sender (the client)
            socket.send(newPacket);
        

【参考方案1】：

搞定了。 正在重复使用同一个数据包。