java检测QQ是否在线

 package mylib.webxml;
//~--- JDK imports ------------------------------------------------------------
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
 *
 * @author jmp esp
 * @version 1.0
 *
 */
public class CheckQQ {
    // 查询后返回的状态
    private final static int ERROR_QQ   = 2;
    private final static int OFFLINE_QQ = 1;
    private final static int    ONLINE_QQ = 0;
    //特征码
    private final static String ONLINE=">Y<";
    private final static String OFFLINE=">N<";
   
  
    private final static String WEBXML_QQ =
        "http://webservice.webxml.com.cn/webservices/qqOnlineWebService.asmx/qqCheckOnline?qqCode=";
    /**
     * 判断QQ是否在线
     * @param qq
     * @return 在线:0|不在线:1|出现错误:2
     */
    public static int isOnline(String qq) {
        URL               url  = null;
        HttpURLConnection http = null;
        InputStream       in   = null;
        try {
            url  = new URL(WEBXML_QQ + qq);
            http = (HttpURLConnection) url.openConnection();
            http.connect();
            i