Android: securityException: "destination must be on external storage"

Question

I've searched thoroughly the web to find an answer, but with no result. I've implemented some "preferences" in my Android app, including the ability to save files in any location you want. If I choose a path on the so-called "integrated sdcard", everything is OK. But I also have a "real" external sdcard, which is mounted (in my case) in `/storage/sdcard1` symlinked to `/extSdCard` and `/mnt/extSdCard` (While the "internal" sdcard is `/storage/sdcard0` with symlinks to `/sdcard` and `/mnt/sdcard`). On ICS I had the external at `/emmc` plus some more links I don't remember. The problem is that if I choose a path pointing to this `extSdCard`, the app creates the folders structure but then doesn't write the downloaded file, ending with the "SecurityException" "destination must be on external storage". But this path IS on an external storage! More: if there are problems of writing permissions, why does it create the folders? (`android.permission.WRITE_EXTERNAL_STORAGE` is present in the ma…

Accepted Answer

According to THIS ARTICLE by Jeremy Meiss (jerdog) and THIS LINK by Chainfire, this behavior should be "normal", as the time being. The WRITE_MEDIA_STORAGE permission should be needed, but this is granted to system apps only.

As a workaround, in my activity I handle this `SecurityException` like this (in pseudo-code):

```
Intent intent = new Intent(MyActivity.this, DownloadsService.class);

try {
    intent.putExtra("COPY", false);
    enqueue = dm.enqueue(request);
    Log.d(DEBUG_TAG, "_ID " + enqueue + " enqueued");
} catch (SecurityException e) {
    Log.w(DEBUG_TAG, e.getMessage());

// handle the path on etxSdCard here:
    showSomeInfo();
    intent.putExtra("COPY", true);
    tempDownloadToSdcard(request);
}

startService(intent);
```

In `DownloadsService` I have a BroadcastReceiver where I handle the finished download; in its `onStartCommand` I retrieve the boolean extra as:

```
doCopy = intent.getBooleanExtra("COPY", false);
```

and then inside the receiver:

```
if (doCopy) copyFileToExtSdCard();
```

Hope this clarifies and helps.

Android: securityException: "destination must be on external storage"

Solution

Problem