How can I access a spring bean in Activiti JavaDelegate?

Question

I\'m trying to get a simple Spring example to work with Activiti 5.5, and having some trouble. I\'m using the process engine configured with activiti under %activiti_home%/a

Answer 1

One of my project uses Activiti with spring. I think that JavaDelagate can be the problem. You can call from activiti's service task every spring bean this way:

bean definition:

<bean id="exampleBean" class="org.bpmn.examples.ExampleBean"/>

activiti xml:

<serviceTask id="servicetask" name="Example" activiti:expression="${exampleBean.doSomething()}"></serviceTask>

You can also pass parameters to the functions for example process variables:

<serviceTask id="servicetask" name="Example" activiti:expression="${exampleBean.doSomething(processVariable)}"></serviceTask>

I always use service tasks this way, and haven't got problem with singleton beans. Hope it helps. Please take a comment, if I didn't understand your problem.

UPDATE:

My project uses activiti like an embedded workflow engine. Activiti uses the same applicationContext with my webapp.

My process engine configuration:

<bean id="processEngineConfiguration" class="org.activiti.spring.SpringProcessEngineConfiguration">
        <property name="databaseType" value="mssql" />
        <property name="dataSource" ref="dataSource" />
        <property name="transactionManager" ref="transactionManager" />
        <property name="databaseSchemaUpdate" value="true" />
        <property name="jobExecutorActivate" value="true" />
        <property name="deploymentResources" value="classpath*:/diagrams/*.bpmn20.xml" />           
    </bean> 


    <bean id="processEngine" class="org.activiti.spring.ProcessEngineFactoryBean">
        <property name="processEngineConfiguration" ref="processEngineConfiguration" />
    </bean>

Answer 2

My guess ist that activiti will indeed always create a new instance because activiti is not aware of the fact that it should retrieve an instance from the spring container.

If you haven't checked this resource yet:

http://www.activiti.org/userguide/index.html#springintegration

maybe it's what you need (i.e. ProcessEngineFactoryBean)

Answer 3

I'm using @Autowired

to bring in my dependencies. Since the JavaDelegate is not instantiated by Spring, I call

applicationContext.getAutowireCapableBeanFactory().autowireBean(this);

in the constructor of my Delegate's Superclass, which injects all dependencies into the Delegate. You might wonder where to get the applicationContext from, http://sujitpal.blogspot.com/2007/03/accessing-spring-beans-from-legacy-code.html provides you with the answer.