title: Spring Integration Gateway reply channel when method return is void
body: <p>I've questions/clarifications-to-make regarding SI gateway feature:</p>
  
  <p>If my gateway interface is defined as below:</p>
  
  <pre><code>public interface MyGateway{
     public void myGatewayMethod(Message&lt;?&gt; inMessage);
  }
  </code></pre>
  
  <p>And my gateway configuration defined as below:</p>
  
  <pre><code>&lt;int:gateway id="mySvcGateway"
                   service-interface="com.myCompany.myPkg.MyGateway"
                   error-channel="globalExceptionHandlerChannel"&gt;
  
          &lt;int:method name="myGatewayMethod" request-channel="myGatewayReqChannel" /&gt;     
      &lt;/int:gateway&gt;
  </code></pre>
  
  <p>My questions/clarifications-to-make are : </p>
  
  <p>1) Since the gateway service interface method is returning void, does the Gateway proxy bean still look for a response on the "default-reply-channel" or the user defined "reply-channel" ?</p>
  
  <p>2) In other words, do I still need to mention <code>reply-channel="nullChannel"</code> (or <code>default-reply-channel="nullChannel"</code>) ?</p>
  
  <p>OR</p>
  
  <p>since the method return is void, gateway automatically will understand no to listen to the reply channel ?</p>
  
  <p>3) Can I still add <code>reply-timeout</code> attribute to this configuration OR it will not make sense since there is no reply expected ?</p>
  
  <p>In similar context, if I add another method in the service interface method as below:</p>
  
  <pre><code>public interface MyGateway{
         public void myGatewayMethod(Message&lt;?&gt; inMessage);
         public Object myGatewayMethod2(Message&lt;?&gt; inMessage);
      }
  </code></pre>
  
  <p>and add this method in my gateway config as below:</p>
  
  <pre><code>&lt;int:gateway id="mySvcGateway"
                       service-interface="com.myCompany.myPkg.MyGateway"
                       error-channel="globalExceptionHandlerChannel"&gt;
  
              &lt;int:method name="myGatewayMethod" request-channel="myGatewayReqChannel" /&gt; 
  &lt;int:method name="myGatewayMethod2" request-channel="myGatewayReqChannel2" /&gt;   
          &lt;/int:gateway&gt;
  </code></pre>
  
  <p>4) In this case I would believe I need to define <code>reply-channel</code>, correct ?</p>
  
  <p>5) The <code>default-reply-channel</code> may not work for this case as for one method gateway expects a response and not for other, correct ?</p>
  
  <p>6) If yes, then for the method that returns void, do I need to explicitly mention <code>reply-channel="nullChannel"</code> ?</p>
  
  <p>Thanks to confirm.</p>