Question

我有以下UDP客户端和servcer类，我正在尝试将一些字符串从UDPClient发送到另一个类＆＃39; UDPServer＆＃39;在localhost和端口7777的同一个java项目中。我遇到的问题是我没有在UDPClient类的UDPServer类中收到任何内容。有谁知道问题出在哪里？

我感谢任何帮助！

UDPClient

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;


class UDPClient {

    public static void main(String args[]) throws Exception {
        String aString = "Hello World";
        DatagramSocket clientSocket = new DatagramSocket();
        InetAddress IPAddress = InetAddress.getByName("localhost");
        byte[] sendData = new byte[1024];
        byte[] receiveData = new byte[1024];
        sendData = aString.getBytes();
        DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 7777);
        clientSocket.send(sendPacket);
        DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
        clientSocket.receive(receivePacket);
        String modifiedSentence = new String(receivePacket.getData());
        System.out.println("FROM SERVER:" + modifiedSentence);
        clientSocket.close();
    }
}

UDPServer

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;


class UDPServer {

        public static void main(String args[]) throws Exception {
            DatagramSocket serverSocket = new DatagramSocket(7777);
            byte[] receiveData = new byte[1024];
            byte[] sendData = new byte[1024];
            while (true) {
                DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
                serverSocket.receive(receivePacket);
                String sentence = new String(receivePacket.getData());
                System.out.println("RECEIVED: " + sentence);
                InetAddress IPAddress = receivePacket.getAddress();
                int port = receivePacket.getPort();
                String capitalizedSentence = sentence.toUpperCase();
                sendData = capitalizedSentence.getBytes();
                DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, port);
                serverSocket.send(sendPacket);
            }
        }
}

Answer 1

您好试着检查端口分配有什么问题，因为您的代码工作正常。

启动服务器并运行以下命令：

窗

 netstat -aon | FINDSTR 7777

Linux的：

 netstat -aon | grep 7777

如果pid与运行UDPServer相同，您应该看到PID检查。还检查防火墙可能有问题吗？

UDPServer不接收来自UDPClient的已发送数据

1 个答案: