activiti7實現流程撤回的兩種思路

一、使用BpmnModel

/**
* @param processInstanceBusinessKey BUSINESS_KEY_
* @param userName 當前用戶
**/
public void rollBackToAssignWoekFlow(String processInstanceBusinessKey, String userName){
        ProcessInstance processInstance = runtimeService.createProcessInstanceQuery().processInstanceBusinessKey(processInstanceBusinessKey).singleResult();
        if(processInstance == null) {
            throw new CustomException("撤回失敗，失敗原因：未查到流程信息！");
        }

        String processInstanceId = processInstance.getProcessInstanceId();

        //獲取流程模型
        BpmnModel bpmnModel = repositoryService.getBpmnModel(processInstance.getProcessDefinitionId());
        if (null == bpmnModel) {
            throw new CustomException("撤回失敗，失敗原因：未查到流程信息！");
        }

        Process process = bpmnModel.getProcesses().get(0);

        // 當前待辦的任務(激活的任務)
        org.activiti.engine.task.Task task = taskService.createTaskQuery().processInstanceId(processInstanceId).active().singleResult();

        // 獲取當前節點
        FlowNode currentFlowNode = (FlowNode) bpmnModel.getMainProcess().getFlowElement(task.getTaskDefinitionKey());
        // List<SequenceFlow> outgoingFlows1 = currentFlowNode.getOutgoingFlows();

        // 退回的目標節點(當前用戶已辦理的最新節點)
        List<HistoricTaskInstance> list = historyService.createHistoricTaskInstanceQuery().processInstanceId(processInstanceId)
                .taskAssignee(userName).orderByHistoricTaskInstanceEndTime().desc().list();
        HistoricTaskInstance historicTaskInstance = list.get(0);
        FlowNode targetFlowNode = (FlowNode) process.getFlowElement(historicTaskInstance.getTaskDefinitionKey());

        // 動態創建從當前任務節點到目標節點的連線
        SequenceFlow sequenceFlow4 = genarateSequenceFlow("test001","test-name",currentFlowNode,targetFlowNode,null,process);
        // currentFlowNode.getOutgoingFlows().clear();
        List<SequenceFlow> oldOutgoingFlows = currentFlowNode.getOutgoingFlows();
        // 將當前節點的向外連線設置成創建的連線
        currentFlowNode.setOutgoingFlows(List.of(sequenceFlow4));
        task.setAssignee(userName);
        taskService.complete(task.getId());    // 完成任務
        currentFlowNode.setOutgoingFlows(oldOutgoingFlows);    // 完成任務后將原來的連線設置回當前任務節點
    }

二、使用流程圖設計撤回

在設計bpmn流程圖時添加一個排他網關，使用表達式控制流程撤回（想到於退回功能）。