code: public static boolean isUrl(String resourceLocation) {
  		return (resourceLocation != null &&
  				(resourceLocation.startsWith(ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX) ||
  						ResourceUtils.isUrl(resourceLocation)));
  	}
docs: Return whether the given resource location is a URL: either a
  special "classpath" or "classpath*" pseudo URL or a standard URL.
  @param resourceLocation the location String to check
  @return whether the location qualifies as a URL
  @see ResourcePatternResolver#CLASSPATH_ALL_URL_PREFIX
  @see java.net.URL