title: Jackson: Ignore Json configuration value
body: <p>I have the following json file:</p>
  
  <pre><code>
  {
    "segments": {        
              "externalId": 123, 
              "name": "Tomas Zulberti", 
              "shouldInform": true, 
              "id": 4
     }
  }
  </code></pre>
  
  <p>But the java model is as follows:</p>
  
  <pre><code>
  public class Segment {
  
      private String id;
      private String name;
      private boolean shouldInform;
  
      // getter and setters here...
  }
  </code></pre>
  
  <p>When Jackson is parsing it raises an exception becuase there is no getter or setter for the field "externalId". It there a decorator that can be used to ignore a json field?</p>