code: public static String getExtension(final String fileName, final boolean withPoint) {
  		final int lastIndexOf = fileName.lastIndexOf(".");
  		if (!withPoint) {
  			return fileName.substring(lastIndexOf + 1);
  		}
  		return fileName.substring(lastIndexOf);
  	}
docs: Gets the extension.
  
  @param fileName  the file name
  @param withPoint the with point
  @return the extension