title: How to get Data from firebase I tried it many time but not accessing?
body: <p>I am accessing data from firebase but its not working why?</p>
  <pre><code>   ref.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
      // ...
    }
  
    @Override
    public void onCancelled(DatabaseError databaseError) {
      // ...
    }
  });
  </code></pre>
  <p>ref contain error</p>