code: public static void isReadable(final File file, String message) throws IllegalArgumentException {
          notNull(file, message);
          if (!file.exists() || !file.isFile() || !file.canRead()) {
              throw new IllegalArgumentException(message);
          }
      }
docs: Checks that the specified String is not null or empty and represents a readable file, throws exception if it is empty or
  null and does not represent a path to a file.
  
  @param path The path to check
  @param message The exception message
  @throws IllegalArgumentException Thrown if path is empty, null or invalid