完善撤回流程

anrui-flowable/anrui-flowable-biz/src/main/java/com/yxt/anrui/flowable/biz/flowtask/FlowTaskService.java

@@ -1156,7 +1156,12 @@ public class FlowTaskService extends MybatisBaseService<FlowTaskMapper, FlowTask
     private String getTaskId(String currentActivityId, String processInstanceId, String processDefinitionId) {
         BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId);
         FlowNode flowNode = (FlowNode) bpmnModel.getFlowElement(currentActivityId);
-        SequenceFlow sequenceFlow = flowNode.getIncomingFlows().get(0);
+        List<SequenceFlow> list=flowNode.getIncomingFlows();
+        if(list.size()==0){
+            return "";
+        }
+        SequenceFlow sequenceFlow = list.get(0);
+
 // 获取上一个节点的activityId
         String sourceRef = sequenceFlow.getSourceRef();
         HistoricActivityInstance historicActivityInstance = historyService.createHistoricActivityInstanceQuery().activityId(sourceRef)
@@ -1183,6 +1188,9 @@ public class FlowTaskService extends MybatisBaseService<FlowTaskMapper, FlowTask
         // taskService.addComment(currentTask.getId(), execution.getProcessInstanceId(), body.get("msg").toString());
         // FlowNode flowNode2 = (FlowNode)bpmnModel.getFlowElement(sourceRef);
         String taskId = getTaskId(currentActivityId, historicTaskInstance.getProcessInstanceId(), historicTaskInstance.getProcessDefinitionId());
+        if(StringUtils.isBlank(taskId)){
+            return new ResultBean<List<LatestTaskVo>>().fail().setMsg("流程找不到上一环节，撤回操作失败！").setData(new ArrayList<>());
+        }
         HistoricTaskInstance historicTaskInstance1 = historyService.createHistoricTaskInstanceQuery().taskId(taskId).singleResult();
         String assignee = historicTaskInstance1.getAssignee();
         String userSid = flowTaskVo.getUserSid();