I took this from jboss esb quickstart examples a very easy but informative use case.
Integration between jbpm and esb via EsbActionHandler it's what I'm dreaming :-) (and I think customers too) to have in a bpmn 2 workflow.
<?xml version="1.0" encoding="UTF-8"?>
<process-definition
name="processDefinition2">
<start-state name="start">
<event type="node-leave">
<action name="action1" class="org.jboss.soa.esb.samples.quickstarts.bpm_orchestration1.process_actions.MyBPMActionHandler" config-type="bean"></action>
</event>
<transition to="node1"></transition>
</start-state>
<node name="node1">
<action name="action2" class="org.jboss.soa.esb.services.jbpm.actionhandlers.EsbActionHandler">
<esbCategoryName>BPM_Orchestration_Service1</esbCategoryName>
<esbServiceName>Service1</esbServiceName>
<bpmToEsbVars>
<mapping bpm="theBody" esb="BODY_CONTENT" />
</bpmToEsbVars>
<esbToBpmVars>
<mapping esb="BODY_CONTENT" bpm="theBody" />
</esbToBpmVars>
</action>
<transition to="node2"></transition>
</node>
<node name="node2">
<action name="action2" class="org.jboss.soa.esb.services.jbpm.actionhandlers.EsbActionHandler">
<esbCategoryName>BPM_Orchestration_Service2</esbCategoryName>
<esbServiceName>Service2</esbServiceName>
<bpmToEsbVars>
<mapping bpm="theBody" esb="BODY_CONTENT" />
</bpmToEsbVars>
<esbToBpmVars>
<mapping esb="BODY_CONTENT" bpm="theBody"/>
</esbToBpmVars>
</action>
<transition to="node3"></transition>
</node>
<node name="node3">
<action name="action2" class="org.jboss.soa.esb.services.jbpm.actionhandlers.EsbActionHandler">
<esbCategoryName>BPM_Orchestration_Service3</esbCategoryName>
<esbServiceName>Service3</esbServiceName>
<bpmToEsbVars>
<mapping bpm="theBody" esb="BODY_CONTENT" />
</bpmToEsbVars>
<esbToBpmVars>
<mapping esb="BODY_CONTENT" bpm="theBody"/>
</esbToBpmVars>
</action>
<transition to="Send Results"></transition>
</node>
<end-state name="end1"></end-state>
<node name="Send Results">
<event type="node-enter">
<action name="action1" class="org.jboss.soa.esb.samples.quickstarts.bpm_orchestration1.process_actions.MyBPMActionHandler" config-type="bean"></action>
</event>
<action name="action2" class="org.jboss.soa.esb.services.jbpm.actionhandlers.EsbActionHandler">
<esbCategoryName>BPM_Orchestration_ResultsService</esbCategoryName>
<esbServiceName>ResultsService</esbServiceName>
<bpmToEsbVars>
<mapping bpm="theBody" esb="BODY_CONTENT" />
</bpmToEsbVars>
<esbToBpmVars>
<mapping esb="BODY_CONTENT" bpm="theBody"/>
</esbToBpmVars>
</action>
<transition to="end1"></transition>
</node>
</process-definition>