title: spring integration: service activator requires-reply="false" usage
body: <p>Why am I receiving the below exception even after I've specified <code>requires-reply="false"</code></p>
  
  <p><strong>Exception</strong></p>
  
  <p><em>org.springframework.integration.support.channel.ChannelResolutionException: no output-channel or replyChannel header available</em></p>
  
  <p><strong>Config</strong></p>
  
  <pre><code>&lt;beans xmlns="http://www.springframework.org/schema/beans"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns:int="http://www.springframework.org/schema/integration"
      xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
          http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration-2.1.xsd"&gt;
  
      &lt;int:channel id="inChannel"&gt;
  
      &lt;/int:channel&gt;
  
      &lt;bean id="upperService" class="sipackage.service.UppercaseService"&gt;&lt;/bean&gt;
  
      &lt;int:service-activator requires-reply="false" input-channel="inChannel" ref="upperService" method="toUpper"&gt;&lt;/int:service-activator&gt;
  &lt;/beans&gt;
  </code></pre>
  
  <p><strong>JUnit</strong></p>
  
  <pre><code>@RunWith(SpringJUnit4ClassRunner.class)
  @ContextConfiguration(locations={"/META-INF/spring/integration/sample.xml"})
  public class ChannelTest {
  
      @Autowired MessageChannel inChannel;
  
      @Test
      public void test() {
  
          boolean sendOutcome=inChannel.send(MessageBuilder.withPayload("Hello, there 1!").build());
          assertTrue(sendOutcome);
  
          sendOutcome=inChannel.send(MessageBuilder.withPayload("Hello, there 2!").build());
          assertTrue(sendOutcome);
      }
  
  }
  </code></pre>
  
  <p><strong>Service</strong></p>
  
  <pre><code>public class UppercaseService {
  
  public String toUpper(String msg)
  {
      return msg.toUpperCase();
  }
  }
  </code></pre>