I got an error,when develop Jbpm6 with Spring:Could not commit session or rollback

[billdone]

I don't know,how to config taskService beans,how to use JTATransactionManager here,whatever i debug the project got the error : Cannot resolve reference to bean 'taskService' while setting bean property 'taskService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'taskService': FactoryBean threw exception on object creation; nested exception is java.lang.RuntimeException: Could not commit session or rollback