code: public static void save(byte[] bytes,String filePath,String fileName) throws IOException {
          Path path = Paths.get(filePath, fileName);
          mkirDirs(path.getParent());
          String pathStr = path.toString();
          File file = new File(pathStr);
          write(bytes,file);
      }
docs: save bytes into file
  @param bytes
  @param filePath
  @param fileName
  @throws IOException