title: Spring Integration, how can I pass inbound http request through outbound gateway?
body: <p>I'm trying to implement some sort of proxy as part of my data flow, I want to receive a http-request on my <em>inbound</em> gateway and pass it through <em>outbound</em> gateway. I want preserve all query string parameters. My gateways configuration is:</p>
  
  <pre><code>&lt;int:channel id="searchRequestChannel" /&gt;
  &lt;int:channel id="searchReplyChannel" /&gt;
  
  &lt;int-http:inbound-gateway id="searchRequestInboundGateway"      
      supported-methods="GET" 
      request-channel="searchRequestChannel"
      reply-channel="searchReplyChannel"      
      path="/services/normalization"
      reply-timeout="50000"
  /&gt;
  
  &lt;int-http:outbound-gateway id="searchServiceGateway"
      http-method="GET"
      request-channel="searchRequestChannel"
      url="http://localhost:8080/query"
      extract-request-payload="false"
      expected-response-type="java.lang.String"
      reply-timeout="50000"
      charset="UTF-8"
  /&gt;
  </code></pre>
  
  <p>I expected that it would work as follows:</p>
  
  <ul>
  <li><p>Client send request to the inbound gateway <em>/services/normalization</em>:</p>
  
  <p>GET /services/normalization q=cat&amp;exclude=black</p></li>
  <li><p>Inbound gateway receives request and send it through <em>searchRequestChannel</em> to the <em>outbound</em> gateway.</p></li>
  <li><p>Outbound gateway sends whole request to the external service:</p>
  
  <p>GET /query q=cat&amp;exclude=black</p></li>
  </ul>
  
  <p>But on practice, outbound gateway sends empty request that does not contains any query arguments:</p>
  
  <pre><code>GET /query
  </code></pre>
  
  <p>So my question, what's easiest way to send the http-request that was accepted on inbound gateway through outbound gateway. In other words how can I implement simple proxy by spring integration tools? </p>