title: How to configure JacksonJaxbJsonProvider in a single line of code?
body: <p>I use Jackson for JSON serialisation in a REST application like this:</p>
  
  <pre><code>import javax.ws.rs.core.Application;
  
  import org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider;
  import org.codehaus.jackson.map.SerializationConfig;
  
  public class MyApplication extends Application {
  
      public Set&lt;Class&lt;?&gt;&gt; getClasses() {
          Set&lt;Class&lt;?&gt;&gt; classes = new HashSet&lt;Class&lt;?&gt;&gt;();
          classes.add(MyResource1.class);
          classes.add(MyResource2.class);
          ...
          return classes;
      }
  
      public Set&lt;Object&gt; getSingletons() {
          Set&lt;Object&gt; singletons = new HashSet&lt;Object&gt;();
          singletons.add(new JacksonJaxbJsonProvider().configure(
              SerializationConfig.Feature.WRITE_NULL_PROPERTIES, false)); // (*)
          return singletons;
      }
  
  }
  </code></pre>
  
  <p>(*) Necessary otherwise fields annotated with @XmlElementRef will appear in JSON output as <code>"myField": null</code> when null (instead of not appearing), while it's fine for fields annotated with @XmlElement.</p>
  
  <p>However the use of <code>SerializationConfig.Feature.WRITE_NULL_PROPERTIES</code> is deprecated in favor of <code>SerializationConfig.setSerializationInclusion(..)</code> (1)
  which itself is deprecated in favor of <code>SerializationConfig.withSerializationInclusion(..)</code> or <em>configure through ObjectMapper</em> (2)</p>
  
  <p>But what I think is done using <code>new JacksonJaxbJsonProvider().configure(..)</code> is indeed configuring an ObjectMapper (I took a look at the code).</p>
  
  <p>So my question is: how do I configure this properly without using any deprecated property and without (re)creating new config class(es)?</p>
  
  <p>(1) <a href="http://jackson.codehaus.org/1.9.4/javadoc/org/codehaus/jackson/map/SerializationConfig.Feature.html#WRITE_NULL_PROPERTIES" rel="nofollow noreferrer">http://jackson.codehaus.org/1.9.4/javadoc/org/codehaus/jackson/map/SerializationConfig.Feature.html#WRITE_NULL_PROPERTIES</a></p>
  
  <p>(2) <a href="http://jackson.codehaus.org/1.9.4/javadoc/org/codehaus/jackson/map/SerializationConfig.html#setSerializationInclusion(org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion)" rel="nofollow noreferrer">http://jackson.codehaus.org/1.9.4/javadoc/org/codehaus/jackson/map/SerializationConfig.html#setSerializationInclusion(org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion)</a></p>