一.文件相關

1.cache.txt: open failed: EROFS (Read-only file system)

• 原因：

ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream("test.txt"));

現在有些手機不允許我們直接向sd card上寫東西，因此做如下修改：

String fname = Environment.getExternalStorageDirectory() + "/test.txt";
ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream(fname));