title: Spring: RestTemplate returns null object
body: <p>With the below GET request:</p>
  
  <pre><code>ResponseEntity&lt;String&gt; entity = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, String.class );
  entity.getBody();
  </code></pre>
  
  <p>returns a JSON String like this: </p>
  
  <pre><code>{"userRegistrations":[{"userRegistrationToken":"fb398972","userRegistrationTokenAlias":"87f15f8"}]}
  </code></pre>
  
  <p>But I want to make this work with an object not with a string. So with the code below I receive a UserRegistrations object with a null UserTokenResponse List</p>
  
  <pre><code>ResponseEntity&lt;UserRegistrations&gt; entity = restTemplate.exchange(uri, HttpMethod.GET, requestEntity, UserRegistrations.class );
  entity.getBody();
  </code></pre>
  
  <p>And my domain class looks like this:</p>
  
  <pre><code>public class UserRegistrations {
      List&lt;UserTokenResponse&gt; userRegistrationList;
      //..getters and setters
  }
  
  public class UserTokenResponse {
     private String userRegistrationToken;
     private String userRegistrationTokenAlias;
     //getters and setters
  }
  </code></pre>
  
  <p>What am I missing?</p>