Question

写入失败时会调用该方法，该方法会关闭 FileOutputStream，并且从备份文件恢复文件内容。

public void failWrite(FileOutputStream str) {
  if (str != null) {
    FileUtils.sync(str);
    try {
      str.close();
      mBaseName.delete();
      mBackupName.renameTo(mBaseName);
    } catch (IOException e) {
      Log.w("AtomicFile", "failWrite: Got exception:", e);
    }
  }
}