code: private void chmod(AlluxioURI path, String modeStr, boolean recursive) throws
        AlluxioException, IOException {
      Mode mode = ModeParser.parse(modeStr);
      SetAttributePOptions options =
          SetAttributePOptions.newBuilder().setMode(mode.toProto()).setRecursive(recursive).build();
      mFileSystem.setAttribute(path, options);
      System.out
          .println("Changed permission of " + path + " to " + Integer.toOctalString(mode.toShort()));
    }
docs: Changes the permissions of directory or file with the path specified in args.
  
  @param path The {@link AlluxioURI} path as the input of the command
  @param modeStr The new permission to be updated to the file or directory
  @param recursive Whether change the permission recursively