原文地址:http://blog.csdn.net/xxhhbb1538/article/details/53116793
在业务场景中,如果需要调用其他流程,我们可以使用callactivity,通过activiti:in,我们可以将主流程的参数传递给子流程,通过activiti:out可以将子流程执行结束后的参数返回给主流程,在单实例情况下,是没有问题的。
但是,当我们调用的子流程数量是不定的,且每个子流程都不一样时,我们可以通过设置调用活动为multi-instance,将子流程运行时动态传递给工作流引擎,如下:
- <callActivity id="call" name="子流程调用" calledElement="${subprocess}">
- <extensionElements>
- <activiti:in source="businessId" target="businessId"/>
- <activiti:in source="businessTable" target="businessTable"/>
- <activiti:out source="cancelled" target="cancelled"/>
- </extensionElements>
- <multiInstanceLoopCharacteristics isSequential="false" activiti:collection="${subprocesslist}" activiti:elementVariable="subprocess">
- <completionCondition>${cancelled=='1'}</completionCondition>
- </multiInstanceLoopCharacteristics>
- </callActivity>
这种情况下,activiti:in依然可以传递参数给子流程,但是activiti:out无法返回子流程的值给主流程,
org.activiti.engine.impl.bpmn.behavior.CallActivityBehavior中,单实例情形中,流程完成前会将子流程的变量传递给父流程
org.activiti.engine.impl.bpmn.behavior.MultiInstanceActivityBehavior中,多实例情形中,流程完成前直接忽略了子流程变量的处理,所以activiti:out中得不到值
- public void completing(DelegateExecution execution, DelegateExecution subProcessInstance) throws Exception {
- // only data. no control flow available on this execution.
- // copy process variables
- for (AbstractDataAssociation dataOutputAssociation : dataOutputAssociations) {
- Object value = null;
- if (dataOutputAssociation.getSourceExpression()!=null) {
- value = dataOutputAssociation.getSourceExpression().getValue(subProcessInstance);
- }
- else {
- value = subProcessInstance.getVariable(dataOutputAssociation.getSource());
- }
- execution.setVariable(dataOutputAssociation.getTarget(), value);
- }
- }
- // required for supporting external subprocesses
- public void completing(DelegateExecution execution, DelegateExecution subProcessInstance) throws Exception {
- }
解决方案:
将
MultiInstanceActivityBehavior类复制一份到项目中,补充comleting方法:
调用CallActivityBehavior
的completing方法,完成变量的传递。
下载
MultiInstanceActivityBehavior类