title: How to exclude null-value fields when using Flexjson?
body: <p>I am serializing a class like this into JSON using Flexjson:</p>
  
  <pre><code>public class Item {
      private Long id;
      private String name;
      private String description;
      ...
  
      // Getters and setters
      ...
  }
  </code></pre>
  
  <p>Many of the Item fields can be null (e.g., description). Consequently, when such an Item object is serialized using Flexjson, I get the following JSON:</p>
  
  <pre><code> {"id":62,"name":"Item A","description":null,...}
  </code></pre>
  
  <p>Since, as I already mentioned, an Item object may contain many null-value fields, the outcoming JSON is longer than effectively needed. This is in so far a problem, because I would like to send the generated JSON from a web server to a mobile client over a wireless connection via WiFi, 3G, EDGE or GPRS (i.e., more bandwidth is required, which results in less speed). </p>
  
  <p>Therefore, I wanted to ask how it is possible to (efficiently) exclude null-value attributes using Flexjson? </p>
  
  <p>Thanks!</p>