Multiple Apps Use Same Content Provider

Multiple Apps use same content provider

ContentProviders are identified by the authority, so it needs to be unique. I don't think there are any tricks around that.

Additionally, there's a bug in the Android platform that also prevents using the same classname for two different ContentProviders, even if they have different authority and are contained in separate APKs. See the bug here.

The solution I advise for you is to create the abstract provider class in your library project, and then extend it with a unique name in each of the individual applications. To make this practical you will probably need to create a script to generate/modify the individual manifests and contentprovider classes.

Hope this helps.

Private Content Provider shared among my apps only

android:grantUriPermissions="true" doesn't work when android:exported is set to false

Yes, it does.

However, android:grantUriPermissions may not be relevant for your use case, particularly if Z is its own standalone app. Z would have to be the one calling into A/B/C using an Intent with the FLAG_GRANT* flag, and I am guessing that this would not fit your plan.

If, as I suspect, A/B/C need to access Z independently of Z telling them that it can be accessed and granting the Uri-specific permissions, the standard approach would be to use a custom signature-level <permission>. You would then defend export the provider and defend it with that permission using android:permission in the <provider>. The theory is that only your app suite can hold that permission, because only your app suite will be signed by that signing key and therefore have a signature match.

(I say "in theory" because there are issues with this approach)

Android Content Provider inside the same application

Not necessary. You just have to create a Content Provider if you want some external application to access your data.

Can multiple ContentProvider's serve the same URI?

Multiple ContentProviders can't do this. The first application that registers a content provider using the element in its manifest has control over the URI pattern. I'm pretty sure that you'll get an installation error if you try to add another provider that uses the same URI pattern. Android keeps track of providers and URIs.

When you see a prompt with multiple apps for handling a file or situation, that's because the apps have specified an with a child that includes
android.intent.category.CATEGORY_ALTERNATIVE or android.intent-category.CATEGORY_SELECTED_ALTERNATVE. In essence, the app or apps are declaring themselves to be alternatives to the action specified in the child. This allows the user to have multiple choices for handling a type of data.

It makes sense to provide alternatives: a user might want to edit a picture, share it via Twitter, or e-mail it.

Note that two content providers can do the same thing, but they can't use the same URI. An app has to make a conscious choice of which one to use, or provide some mechanism of choosing between the two.

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