Why do two ways of building resource URI give different results in Android?

Issue

I am trying to play sound from a notification, so I have code like

Notification notification = new NotificationCompat.Builder(context)
        .setSound(uri)
        // ... more builder options
        .build();

I tried two different ways of constructing the uri. The first was

Uri uri = Uri.parse(String.format("android.resource://%s/%d",
                                  context.getPackageName(),
                                  resourceId));

and the second was

Uri uri = new Uri.Builder().scheme("android.resource")
                           .path("//")
                           .appendPath(context.getPackageName())
                           .appendPath(Integer.toString(resourceId))
                           .build();

If I print the uris generated by each of these techniques, I get an identical string:

android.resource://com.example.notification/2130968576

However, the sound plays when I use the first technique but not when I use the second one. Why is this?

I have observed this behavior on Android 4.3 and Android 4.4, with the v4 support library.

Solution

You have to set the correct authority in your uri instead of prepending //:

Uri uri = new Uri.Builder().scheme("android.resource")
                       .authority(context.getPackageName())
                       .path(Integer.toString(resourceId))
                       .build();

I admit it's confusing since both methods return the same string and compare equal, but that's what fixed it for me.

Answered By - mick88