JAVA如何验证指定QQ用戶状态是否在线

JAVA如何验证指定QQ用戶状态是否在线

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;


public class Qq{

	public static String qUrl = "QQ号码";
	private static int state = 1243;

	public static void main(String[] args) {
		
		String urlQ = "http://wpa.qq.com/pa?p=2:"+qUrl+":41";
		
		try {
			URL url = new URL(urlQ);
			HttpURLConnection httpUrl = (HttpURLConnection) url.openConnection();
			
			if(state==httpUrl.getContentLength())
				System.out.println("QQ用户：["+qUrl+"]状态为在线");
			else
				System.out.println("QQ用户：["+qUrl+"]状态为离线/隐身");
			
		}catch (IOException e) {
			System.out.println("连接此URL"+urlQ+"抛出异常信息");
		}
	}

}