java检测端口号是否被占用的工具类：

 

 

 

package com.frank.util;

import java.io.IOException;

import java.net.InetAddress;

import java.net.Socket;

import java.net.UnknownHostException;

public class NetUtil {

	/***

	 *  true:already in using  false:not using

	 * @param port

	 */

	public static boolean isLoclePortUsing(int port){

		boolean flag = true;

		try {

			flag = isPortUsing("127.0.0.1", port);

		} catch (Exception e) {

		}

		return flag;

	}

	/***

	 *  true:already in using  false:not using

	 * @param host

	 * @param port

	 * @throws UnknownHostException

	 */

	public static boolean isPortUsing(String host,int port) throws UnknownHostException{

		boolean flag = false;

		InetAddress theAddress = InetAddress.getByName(host);

		try {

			Socket socket = new Socket(theAddress,port);

			flag = true;

		} catch (IOException e) {

		}

		return flag;

	}

}