Firebase Firestore retrieve data Synchronously/without callbacks

Question

I am using Cloud Firestore in a separate thread in my Android app, so I don\'t want to use listeners OnSuccessListener and OnFailureListener to run

Answer 1

Your can do something like this on the main thread...

YourObject yourObject = (YourObject)new RunInBackground().
                          execute("someCollection","someDocument").get()

And the background thread is...

public class RunInBackground extends AsyncTask {

  @Override
  protected Object doInBackground(Object[] objects) {

    Task documentSnapshotTask = FirebaseFirestore.getInstance().
             collection((String) objects[0]).document((String) objects[1]).get();

    YourObject obj=null;

    try {
        DocumentSnapshot documentSnapshot = Tasks.await(documentSnapshotTask);

        obj = new YourObject();
        obj.setter(documentSnapshot.get("your field"));

    } catch (ExecutionException e) {
        e.printStackTrace();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    return obj;
  }
}