public static void deleteDirectory(File directoryOrFile) {
    if (!directoryOrFile.exists()) {
      return;
    }

    if (directoryOrFile.isDirectory()) {
      for (File child : directoryOrFile.listFiles()) {
        deleteDirectory(child);
      }
    }
    directoryOrFile.delete();
  }
 public static void cleanupAllAttachments() {
   Utility.deleteDirectory(getAttachmentsDirectory());
 }
 public static void cleanupAttachmentsForCall(UUID uuid) {
   File attachmentsDirectoryForCall = getAttachmentsDirectoryForCall(uuid, false);
   if (attachmentsDirectoryForCall != null) {
     Utility.deleteDirectory(attachmentsDirectoryForCall);
   }
 }