title: JAXB namespace prefixes missing
body: <p>I have generated Java classes from XSD, all works fine from a unmarshalling point of view.</p>
  
  <p>However, when I marshall from JAXB classes I get the following:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;
  &lt;message xmlns="http://poc.cmc.com/ScreenLayout"&gt;
      &lt;Data&gt;
          &lt;Type&gt;Sample&lt;/Type&gt;
       . . .
  &lt;/message&gt;
  </code></pre>
  
  <p>But I need </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8" standalone="yes"?&gt;
  &lt;ns0:message xmlns:ns0="http://poc.cmc.com/ScreenLayout"&gt;
      &lt;ns0:Data&gt;
          &lt;ns0:Type&gt;Sample&lt;/ns0:Type&gt;
      . . .
  </code></pre>
  
  <p>how can I control that from Java?</p>
  
  <p>Thanks a lot</p>