Java可以通过Socket类来检测端口是否被占用：

import java.net.*;  import java.io.*;    public class Main {     public static void main(String[] args) {        Socket Skt;        String host = "localhost";        if (args.length gt; 0) {           host = args[0];        }        for (int i = 0; i < 1024; i++) {           try {              System.out.println("Looking for "+ i);              Skt = new Socket(host, i);              System.out.println("There is a server on port "              + i + " of " + host);           }           catch (UnknownHostException e) {              System.out.println("Exception occured"+ e);              break;           }           catch (IOException e) {           }        }     }  }