Just Spring Integration

Common Endpoints

We have touched upon one of the common endpoints in an earlier chapter—Service Activators. In this section, we will discuss this in detail, and other endpoints, too. First, make sure that you have the integration namespace declared in your XML file for these endpoints:

...
xmlns:int="http://www.springframework.org/schema/integration"

xsi:schemaLocation="http://www.springframework.org/schema/integration 
  http://www.springframework.org/schema/integration/spring-integration-2.1.xsd"
...

Service Activator

The Service Activator is a generic endpoint which invokes a method on a bean whenever a message arrives on the channel. If the method has a return value, then the value will be sent to an output channel if the channel is configured.

Configuring the activator using the namespace is relatively straightforward. Use the service-activator element, setting input-channel and a ref to the bean:

<int:service-activator 
  input-channel="positions-channel"
  ref="newTradeActivator" 
  method="processNewPosition">
</int:service-activator>

<bean id="newTradeActivator" 
  class="com.madhusudhan.jsi.endpoints.common.NewTradeActivator" />

Any message arriving at positions-channel will be passed on to a NewTradeActivator (which the attribute ref points to) and the processNewPosition method is invoked which is declared using the method attribute. If the bean class has only one method, then you do not have to declare the method attribute—the framework resolves it as the service method and invokes it appropriately. ...