java – 检查链接是否损坏

private static boolean isLive(String link){

    HttpURLConnection urlconn = null;
    int res = -1;
    String msg = null;
    try{

        URL url = new URL(link);
        urlconn = (HttpURLConnection)url.openConnection();
        urlconn.setConnectTimeout(10000);
        urlconn.setRequestMethod("GET");
        urlconn.connect();
        String redirlink = urlconn.getHeaderField("Location");
        System.out.println(urlconn.getHeaderFields());
        if(redirlink != null && !url.toExternalForm().equals(redirlink))
            return isLive(redirlink);
        else
            return urlconn.getResponseCode()==HttpURLConnection.HTTP_OK;

    }catch(Exception e){

      System.out.println(e.getMessage());
      return false;

    }finally{

        if(urlconn != null)
            urlconn.disconnect();

    }


}

public static void main(String[] s){

    String link = "http://www.somefakesite.net";
    System.out.println(isLive(link));

}

代码来自http://nscraps.com/Java/146-program-code-broken-link-checker.htm.

此代码为所有网页(包括损坏的网页)提供HTTP 200状态.例如
http://www.somefakesite.net/给出以下标题字段：

{null = [HTTP / 1.1 200 OK],Date = [Sun,2011年5月15日18:51:29 GMT],Transfer-Encoding = [chunked],Keep-Alive = [timeout = 4,max = 100],Connection = [Keep-Alive],Content-Type = [text / html],Server = [Apache / 2.2.15(Win32)PHP / 5.2.12],X-Powered-By = [PHP / 5.2.9-1] }

即使这些网站不存在,如何将其归类为断链？