title: apache camel read headers using spring dsl
body: <p>I am trying to read request headers using Apache camel 2.14.1 "Rest" component. Below is my spring dsl to configure rest component</p>
  
  <pre><code>&lt;rest path="/a"&gt;
              &lt;get uri="/{b}"&gt;
                  &lt;route&gt;
                      &lt;setBody&gt;
                          &lt;simple&gt;${header.b}:${header.headerName}&lt;/simple&gt;
                      &lt;/setBody&gt;
                      &lt;to uri="activemq:queue:requestQueue?replyTo=responseQueue"/&gt;
                  &lt;/route&gt;
              &lt;/get&gt;
  &lt;/rest&gt;
  </code></pre>
  
  <p>When I call this service(http//localhost:8081/test/a/b) by setting the headers (headerName=1) using postman plugin, then my camel configuration is unable to read header values. </p>
  
  <p>As per the documentation, we can read headers using ${in.header.headerName}, which is returning empty in my case.</p>
  
  <p>Please help me to read header values.</p>