How to Convert Firebase data to Java Object…?

Question

Using Firebase Library to send data to the server in the form Message(String, String) added to the HashMap

Exampl

Answer 1

You could make it using a ChildEventListener instead of a ValueEventListener.

For example. I have a class called match with 3 string properties {id, name, photoUrl} then I add all the values in a List. Instead of using a for loop it works for me with this code.

    Query queryRef = mDatabase.child("users").child(user.getUid()).child("matches");

    ChildEventListener listener = new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String previousChildName) {
            Match match = dataSnapshot.getValue(Match.class);
            matchList.add(match);
            mAdapter = new MatchAdapter(getContext(), matchList);
            recyclerView.setAdapter(mAdapter);
        }
        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String previousChildName) {
            Log.d("MESSAGEFRAGMENT", "CHILDCHANGE");
        }
        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {
        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    };
    queryRef.addChildEventListener(listener);