java - Java：显示客户端 IP 和端口号

Question

您好，我写了一个小型 UDP 服务器程序。我知道显示主机 IP 的代码很容易使用以下代码：

System.out.println("Listening Port: " + serverSocket.getLocalPort());
System.out.println("IP: " + myIp.getHostAddress());

有没有办法显示连接到服务器的客户端的 IP 和端口号？

Answer 1

当您收到 UDP 时DatagramPacket，您可以从数据包的来源处检索远程 IPDatagramPacket.getAddress()

编辑 如果您希望获取 IP 地址的字符串表示形式，只需使用DatagramPacket.getAddress().toString().

例子：

DatagramPacket p = new DatagramPacket(buffer, 
buffer.length); 
ds.receive(p);  // Receive data here... 
System.out.println("Received data packet from :"+p.getAddress().toString()); 

Answer 2

About that sample: String clientip = DatagramPacket.getAddress(); why don't you just cast it to String.

String clientip = (String) DatagramPacket.getAddress();

Though i don't really have a Java Compiler at the moment. but just try that. Will get back really soon.