code: protected void processDeleteOnExit() {
      synchronized (deleteOnExit) {
        for (Iterator<Path> iter = deleteOnExit.iterator(); iter.hasNext();) {
          Path path = iter.next();
          try {
            delete(path, true);
          }
          catch (IOException e) {
            LOG.info("Ignoring failure to deleteOnExit for path " + path);
          }
          iter.remove();
        }
      }
    }
docs: Delete all files that were marked as delete-on-exit. This recursively
  deletes all files in the specified paths.