Firebase

FirebaseUtil.java

ValueEventListener postListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        Iterable<DataSnapshot> snapshot = dataSnapshot.child("book").getChildren();
        for (DataSnapshot snapshot1 : snapshot) {
            Book book = snapshot1.getValue(Book.class);
            tvData.setText(book.getName());
        }
        //tvData.setText(book.getName()); Textview e datayı bind ettik.
    }
    @Override
    public void onCancelled(DatabaseError databaseError) {

    }
};
mDatabase.addValueEventListener(postListener);