Question

我写了一个小型客户端 - 服务器应用程序。它应该从客户端发送一个字符串到服务器，服务器应该在控制台上显示它。但是服务器一直在等待数据。看起来数据不会来到服务器。我错了什么？

public class UDPClient {

    public static void main(String[] args) throws IOException {
        BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
        DatagramSocket clientSocket = new DatagramSocket();
        InetAddress IPAdress = InetAddress.getByName("localhost");
        byte[] sendData = new byte[1024];
        String sentence = inFromUser.readLine();
        sendData = sentence.getBytes();
        DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAdress, 4445);
        clientSocket.close();
    }
}

public class UDPServer {

    public static void main(String[] args) throws IOException {
        DatagramSocket serverSocket = new DatagramSocket(4445);
        byte[] receiveData = 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);
        }
    }
}

Answer 1

你忘了实际通过套接字发送包。

只需添加

clientSocket.send(sendPacket);

之前

clientSocket.close();

在UDPClient.main()中

，一切都会有效。

为什么receive（）方法没有从客户端接收数据？

1 个答案: