How to Delete and then Re-initialize Firebase App in android?

Question

I'm try to handle two databases of two different firebase projects. For this I have to first Delete newly initialized app and then have to re-initialized app. For this purpose I'm trying to use but failed everytime.

FirebaseApp.initializeApp(context, firebaseOptions, "secondary").delete();

What should be used to Delete an secondary initialized firebase app? Here's below my code:

 boolean hasBeenInitialized = false;
    List<FirebaseApp> firebaseAppList = FirebaseApp.getApps(Charts.this);

    for (FirebaseApp app : firebaseAppList) {

        if (app.getName().equals("secondary")) {
            hasBeenInitialized = true;

        }
    }

    FirebaseOptions firebaseOptions = new FirebaseOptions.Builder()
            .setApiKey(apiKey)
            .setApplicationId(appId)
            .setDatabaseUrl(databaseLink)
            .build();

    if (!hasBeenInitialized) { //false
        firebaseApp = FirebaseApp.initializeApp(Charts.this, firebaseOptions, "secondary");

    } else {
        firebaseApp = FirebaseApp.getInstance("secondary");

        FirebaseApp.initializeApp(Charts.this, firebaseOptions, "secondary").delete();
        firebaseApp = FirebaseApp.initializeApp(Charts.this, firebaseOptions, "secondary");

              }

    secondaryDatabase = FirebaseDatabase.getInstance(firebaseApp);

`

Answer 1

The Bugs

In your code, you find the secondary instance, but then immediately try to initialize it again throwing an error.

firebaseApp = FirebaseApp.getInstance("secondary");
FirebaseApp.initializeApp(Charts.this, firebaseOptions, "secondary").delete(); // throws IllegalStateException

The fixed form of this would be:

firebaseApp = FirebaseApp.getInstance("secondary");
firebaseApp.delete();

Also, on the last line of your code, you try to get the FirebaseApp for the string value of firebaseApp not "secondary"

secondaryDatabase = FirebaseDatabase.getInstance(firebaseApp);

The fixed from of this would be:

secondaryDatabase = firebaseApp;
// OR
secondaryDatabase = FirebaseDatabase.getInstance("secondary");

Fixed Code

Instead of storing the app instance as firebaseApp at all, just delete/use the instance directly.

List<FirebaseApp> firebaseAppList = FirebaseApp.getApps(Charts.this);

// Delete "secondary" if it exists
for (FirebaseApp app : firebaseAppList) {
    if (app.getName().equals("secondary")) {
        app.delete(); // found "secondary". Delete it
        break;
    }
}

// Build options object
FirebaseOptions firebaseOptions = new FirebaseOptions.Builder()
        .setApiKey(apiKey)
        .setApplicationId(appId)
        .setDatabaseUrl(databaseLink)
        .build();

// Initialize
secondaryDatabase = FirebaseApp.initializeApp(Charts.this, firebaseOptions, "secondary");

// secondaryDatabase is now a FirebaseApp instance for the secondary database