Question

I’m trying to simply write a simple XML file to the SD card and I noticed that my Nexus 4 does write the file, but it is not viewable via the MTP protocol using Windows 7.

code:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    CustomerQueryRqType customerQueryRequest = new CustomerQueryRqType();
    Serializer serializer = new Persister();
    File myFile = new File(Environment.getExternalStorageDirectory() + "/customerQueryRequest.xml");

    try {
        boolean created = myFile.createNewFile();
        serializer.write(customerQueryRequest, myFile);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

I can see the file on the phone itself with Astro File Manager:

but Windows doesn’t see it…:

adb shell on the directory shows:

ls -l
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Alarms
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Android
drwxrwxr-x root     sdcard_rw          2012-11-21 19:30 DCIM
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Download
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Movies
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Music
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Notifications
drwxrwxr-x root     sdcard_rw          2012-11-19 12:06 Pictures
drwxrwxr-x root     sdcard_rw          1970-01-16 20:51 Podcasts
drwxrwxr-x root     sdcard_rw          2012-11-19 13:22 Ringtones
drwxrwxr-x root     sdcard_rw          2012-11-19 14:33 bluetooth
-rw-rw-r-- root     sdcard_rw       79 2012-12-05 22:26 customerQueryRequest.xml
drwxrwxr-x root     sdcard_rw          2012-11-20 02:50 data
-rw-rw-r-- root     sdcard_rw    11394 2012-11-19 13:54 eightpen_custom_gestures
drwxrwxr-x root     sdcard_rw          2012-11-19 13:17 media

What’s going on with my Nexus 4? Why is it hiding my things from Windows?

Answer 1

Seems to be a known issue affecting Android USB file access over MTP. The MTP cache gets out of date until a reboot of the phone.

A workaround is:

• Clear the “Media Storage” app’s data
• Use the SDrescan or the SD Scanner (also works on Android 4.4/5, available on F-Droid) app to force an update

Or just avoid using USB at all. The issue does not affect other methods of accessing the files. For example, try AirDroid to transfer files.

---

Note: This doesn’t work for Android 5.0.2: After clearing “Media Storage” and using an SD Rescanner, the folders appears in Windows 7 as unopenable 4K files. The only solution at that point is to clear once again Media Storage and restart the device