在業務場景中,如果需要調用其他流程,我們可以使用callactivity,通過activiti:in,我們可以將主流程的參數傳遞給子流程,通過activiti:out可以將子流程執行結束後的參數返回給主流程,在單實例情況下,是沒有問題的。
但是,當我們調用的子流程數量是不定的,且每個子流程都不一樣時,我們可以通過設置調用活動爲multi-instance,將子流程運行時動態傳遞給工作流引擎,如下:
<callActivity id="call" name="子流程調用" 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>
這種情況下,activiti:in依然可以傳遞參數給子流程,但是activiti:out無法返回子流程的值給主流程,
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 {
}
解決方案: