Firebase “Failed to convert a value of type java.util.HashMap to int”

Question

At this line of my code in my OnDataChange() method in the ValueEvenListener:

int latest = dataSnapshot.getValue(Integer.class);
         


        

Answer 1

Your ValueEventListener is attached to the whole database.

// This line gets a reference to the whole database
final DatabaseReference database =  FirebaseDatabase.getInstance().getReference();

// This line creates a child DatabaseReference, but you don't assign
// the child to a variable
database.child("Campaigns").child(key).child("count");

// This line adds a ValueEventListener to the whole database
database.addValueEventListener(new ValueEventListener() {

What you want instead is this:

final DatabaseReference database = FirebaseDatabase.getInstance().getReference()
final DatabaseReference countRef = database.child("Campaigns").child(key).child("count")
countRef.addValueEventListener(new ValueEventListener() {
    // ...
});

You can see that in the latter example the ValueEventListener is attached to the child reference, not to the root.