title: apache camel simple language test on null exchange in Bluepring XML not working
body: <p>I'm using Apache Camel 2.17 and using the simple language to catch a null exchange.  It is not working and I've tried several formatting approaches, but it doesn't catch a null.  I believe it is the format/syntax of how I'm using it.  please instruct where I'm going wrong.  thank you!</p>
  
  <pre><code>&lt;process id="_process18" ref="csvMarshallerProcessor"/&gt;
  &lt;process id="toReOrgCSV" ref="reOrgCSVData"/&gt;
  &lt;choice id="_choice13"&gt;
      &lt;when id="_when13"&gt;
          &lt;simple&gt;"${body}" == null&lt;/simple&gt;
          &lt;log id="_log22" message="body is NULL, do not send NULL body!"/&gt;
          &lt;stop id="_stop7"/&gt;
      &lt;/when&gt;
      &lt;otherwise id="_otherwise1"&gt;
  </code></pre>
  
  <p>I've tried </p>
  
  <pre><code>&lt;simple&gt;"${body} == null"&lt;/simple&gt;
  &lt;simple&gt;"${body}" == null&lt;/simple&gt;
  &lt;simple&gt;${body} == null&lt;/simple&gt;
  &lt;simple&gt;${body} == 'null'&lt;/simple&gt;
  </code></pre>
  
  <p>I set the exchange to null in a previous process IF the data is filtered out and ineligiable to send out.  I'd like to just use Camel Spring XML.  </p>
  
  <p>???</p>