public static long length(URL url) throws IOException {
  HTTPResponse http=HTTPEngine.head(url,null,null,-1,true,null,Constants.NAME,null,null);
  return http.getContentLength();
}

public static long length ( URL url ) throws IOException { HTTPResponse http = HTTPEngine . head ( url , null , null , - 1 , true , null , Constants . NAME , null , null ) ; return http . getContentLength ( ) ; }
return the length of a file defined by a url .
