title: firebase child exists or not in android
body: <p>My question is similar to the question posted <a href="https://stackoverflow.com/questions/11420650/proper-use-of-haschild-and-foreach-from-a-reference-in-firebase">here</a></p>
  
  <ol>
  <li>I have a Firebase path called for a users table, say appname/users </li>
  <li>I want to see if a user exists.</li>
  <li>I obtain a reference: Firebase users =
  ref.child('users');</li>
  </ol>
  
  <p>I am wondering if there is an equivalent Java code similar to the javascript answer provided. I ask this because in the latest version of Firebase-client that I am using I am unable to find the method once(), which has been called to see if a child exists or not. </p>
  
  <p>EDIT 1: </p>
  
  <p>I am using the Eclipse IDE for development and I have download the firebase jar from the location specified in the web page. I am unable to use a couple of methods as I do not see any of them being specified. </p>
  
  <pre><code>Firebase ref = new Firebase(url);
  Firebase usersRef = ref.child("users");
  </code></pre>
  
  <p>When I try to use the method once()/ hasChild() the IDE does not show any of these methods being available. I am not sure if it is only at my end or if I need to download and use another jar? 
  <img src="https://i.stack.imgur.com/rkCq1.png" alt="here"></p>
  
  <p>Any suggestions? </p>