Firebase Android method to check existence of user's profile info in Firebase database

Question

I don't get any error message but I want to execute code differently.

If you check following java code, it runs like Tag:1 > Tag:2 > Tag:4 > Tag:5 > Tag:3. I want to run it like Tag:1 > Tag:2 > Tag:3 > Tag:4 > Tag:5.

Basically, I want to check user's profile exist or not before starting of a new activity. I am looking for method that just check the existence of child in the Firebase database. I am not changing any data from database. So, It should not be onDataChange() method. I think, there was once() method available in old Firebase to do the same. Is there any method available?

Thank you

 Log.i("Tag:","1");

    String userId = getUid();

    Log.i("Tag:","2");     
  databaseReference.child("users").child(userId).addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {

                    UserProfile userProfile = dataSnapshot.getValue(UserProfile.class);

                    Log.i("Tag:","3");               

                    if (userProfile == null){
                        //do something

                    } else {
                        //do something
                    }
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });

    Log.i("Tag:","4");
    Log.i("Tag:","5");

Answer 1

From what I can see from your code is:

• You already have the userID of the userProfile
• You are checking whether a profile exists on that specific id or no.

Well, creating an object and checking whether its null or no is definitely one way but Firebase has a pre-defined method for checking whether data exists on that specific node or no:

dataSnapshot.exists()

Returns true if this DataSnapshot contains any data. It is slightly more efficient than using snapshot.val() !== null.

This is what the official docs mention.