title: Jackson JSON not ignoring Objectify Key
body: <p>I'm working on a web application using Spring REST (3.2.8.RELEASE), GAE and Objectify (v 4.0b3).  I'm new to both GAE and Objectify.</p>
  
  <p>The application returns data in JSON format.</p>
  
  <p>I'm getting a 500 error when Jackson serializes the Objectify Key.  So, I tried to use @JsonIgnore as mentioned in this posting <a href="https://stackoverflow.com/questions/11968513/jsonmappingexception-how-to-transfert-a-objectify-entity-with-key-through-res">JsonMappingException: How to transfert a Objectify Entity (with Key) through Restlet</a> .
  But it's still throwing the same 500 error.  I tried to place the @JsonIgnore at the attribute, getter, setter method, but no luck.  </p>
  
  <p>Can someone give me some guidance on what I may be doing incorrectly?  The other option is to write a custom serializer.</p>
  
  <p>Thanks so much in advance for your help.</p>
  
  <pre><code>public class CategoryTrackingCount {
  
      Key&lt;CategoryTracking&gt; categoryTrackingKey;
  
      @JsonIgnore     
      public Key&lt;CategoryTracking&gt; getCategoryTrackingKey() {
          return categoryTrackingKey;
      }
  
      @JsonIgnore
      public void setCategoryTrackingKey(Key&lt;CategoryTracking&gt; categoryTrackingKey) {
          this.categoryTrackingKey = categoryTrackingKey;
      }
  }
  </code></pre>