code: public static String last(String string, char separator)
    {
      if(string == null) {
        return null;
      }
      if(string.isEmpty()) {
        return "";
      }
      return string.substring(string.lastIndexOf(separator) + 1);
    }
docs: Get last string sequence following given character. If separator character is missing from the source string
  returns entire string. Return null if string argument is null and empty if empty.
  
  @param string source string,
  @param separator character used as separator.
  @return last string sequence.