Question

每次我运行客户端时，服务器都会告诉我一个不同的端口号。我搜索了一下，发现当我将端口设置为零时，它会查找可用端口，但我将其更改为我想要的数字public static final int MYPORT = 5555;，并且每次都从服务器获取新的端口号。

这是打印方法：

System.out.printf(" using port %d\n", receivePacket.getPort());

DatagramSocket socket = new DatagramSocket(null);
SocketAddress localBindPoint = new InetSocketAddress(MYPORT); socket.bind(localBindPoint); 
SocketAddress remoteBindPoint = new InetSocketAddress(args[0], Integer.valueOf(args[1]));

Answer 1

我认为你错过了这一点，这段代码在端口5555上侦听：

以下代码中的istruction packet.getPort()返回发送此数据报或从中接收数据报的远程主机上的端口号。

  int MYPORT = 5555;
  DatagramSocket dsocket = new DatagramSocket(MYPORT);
  byte[] buffer = new byte[2048];

  // Create a packet to receive data into the buffer
  DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

  while (true) {
    // Wait to receive a datagram
    dsocket.receive(packet);

    // Convert the contents to a string, and display them
    String msg = new String(buffer, 0, packet.getLength());
    System.out.println(packet.getAddress().getHostName() + ": "
        + msg);

    // Reset the length of the packet before reusing it.
    packet.setLength(buffer.length);

    System.out.printf(" using port %d\n", packet.getPort());
  }

我在本地进行了双重检查：

sudo lsof -iUDP -n -P   | grep 5555
java      1606        freedev    5u  IPv6 0x9ed7290ce134656f      0t0  UDP *:5555

如何在java中的udp（客户端，服务器）程序中设置客户端的端口号？

1 个答案: