Because the Smooks Action can produce a number of different types of result, you need to be able to specify which one you want. The result you choose is then added back to the message payload.
The default ResultType is "STRING". You can change it to "BYTES", "JAVA" or "NORESULT" by setting the "resultType" configuration property.
Specifying a resultType of "JAVA" allows you to select one or more Java Objects from the Smooks ExecutionContext (specifically, the bean context). The javaResultBeanId configuration property complements the resultType property by allowing you to specify a specific bean to be bound from the bean context to the message payload location.
Here is some sample code that binds the "order" bean from the Smooks bean context onto the message as its payload:
<action name="transform" class="org.jboss.soa.esb.smooks.SmooksAction">
<property name="smooksConfig" value="/smooks/order-to-java.xml" />
<property name="resultType" value="JAVA" />
<property name="javaResultBeanId" value="order" />