The integration of jbpm 4.2 with spring 2.5.6 fails.

Using minimal jbpm.cfg.xml

<process-engine-context>
<command-service>
<retry-interceptor />
<environment-interceptor />
<spring-transaction-interceptor />
</command-service>
</process-engine-context>

<transaction-context>
<transaction />
<hibernate-session current="true" />
</transaction-context>

spring bean configuration:

<bean id="jbpmConfiguration" class="org.jbpm.pvm.internal.cfg.SpringConfiguration">
<constructor-arg value="com/psinova/jbpm.cfg.xml" />
</bean>

<bean id="processEngine" factory-bean="jbpmConfiguration" factory-method="buildProcessEngine" />
<bean id="repositoryService" factory-bean="processEngine" factory-method="getRepositoryService" />
<bean id="executionService" factory-bean="processEngine" factory-method="getExecutionService" />

and a NPE is thrown with the following stack trace:

Caused by: java.lang.NullPointerException
at org.jbpm.pvm.internal.cfg.ProcessEngineImpl.checkDb(ProcessEngineImpl.java:177)
at org.jbpm.pvm.internal.cfg.ProcessEngineImpl.buildProcessEngine(ProcessEngineImpl.java:170)
at org.jbpm.pvm.internal.cfg.SpringConfiguration.buildProcessEngine(SpringConfiguration.java:81)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:115)