code: public static void touch(File file) throws FileNotFoundException {
  
          if (!file.exists()) {
              OutputStream out = new FileOutputStream(file);
              try {
                  out.close();
              } catch (IOException e) {
                  // Ignore.
              }
          }
  
          file.setLastModified(System.currentTimeMillis());
      }
docs: Implements the same behavior as the "touch" utility on Unix.
  It creates a new file with size 0 byte or, if the file exists already, it
  is opened and closed without modifying it, but updating the file date and
  time.
  
  @param file The file to "touch."
  
  @throws FileNotFoundException
  If the file is not found.