URLConnection 이용해서 웹페이지 확인

  URL url = null;
  URLConnection uc = null;
  HttpURLConnection connection;
 
  imgPath = "http://www.javaservice.net/adv/J2eeSTUDY.jpg";
  url = new URL(imgPath);
  uc = url.openConnection();
  try
  {
    connection = (HttpURLConnection)uc;

    if(connection.getResponseCode() != 200) //getResponseCode() => 404 (실패)  200(성공)
    { 
       System.out.println("페이지가 없습니다.!!!");
    }
  }
  catch(Exception e){}