Activiti5驳回

在 Activiti 5 中，驳回功能可以通过以下两种方式实现：

1. 使用 `exclusiveGateway` 和 `userTask` 元素：在流程中添加一个 `exclusiveGateway` 元素，将其与要驳回的目标 `userTask` 元素相连。在 `exclusiveGateway` 元素的条件中，判断是否需要驳回，如果需要驳回，则将流程实例的当前任务设置为目标 `userTask` 元素，即可实现驳回功能。

以下是一个示例流程定义文件：

   <?xml version="1.0" encoding="UTF-8"?>
   <definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:activiti="http://activiti.org/bpmn"
       targetNamespace="http://www.activiti.org/processdef">
   
     <process id="process"
         name="Process"
         isExecutable="true">
   
       <startEvent id="startEvent"
           name="Start">
         <outgoing>flow1</outgoing>
       </startEvent>
   
       <userTask id="userTask1"
           name="Task 1">
         <incoming>flow1</incoming>
         <outgoing>flow2</outgoing>
       </userTask>
   
       <exclusiveGateway id="exclusiveGateway"
           name="Gateway">
         <incoming>flow2</incoming>
         <outgoing>flow3</outgoing>
         <outgoing>flow4</outgoing>
       </exclusiveGateway>
   
       <userTask id="userTask2"
           name="Task 2">
         <incoming>flow3</incoming>
         <outgoing>flow5</outgoing>
       </userTask>
   
       <userTask id="userTask3"
           name="Task 3">
         <incoming>flow4</incoming>
         <outgoing>flow6</outgoing>
       </userTask>
   
       <sequenceFlow id="flow1"
           sourceRef="startEvent"
           targetRef="userTask1" />
   
       <sequenceFlow id="flow2"
           sourceRef="userTask1"
           targetRef="exclusiveGateway" />
   
       <sequenceFlow id="flow3"
           sourceRef="exclusiveGateway"
           targetRef="userTask2">
         <conditionExpression xsi:type="tFormalExpression">${rejected}</conditionExpression>
       </sequenceFlow>
   
       <sequenceFlow id="flow4"
           sourceRef="exclusiveGateway"
           targetRef="userTask3">
         <conditionExpression xsi:type="tFormalExpression">${!rejected}</conditionExpression>
       </sequenceFlow>
   
       <sequenceFlow id="flow5"
           sourceRef="userTask2"
           targetRef="endEvent" />
   
       <sequenceFlow id="flow6"
           sourceRef="userTask3"
           targetRef="endEvent" />
   
       <endEvent id="endEvent"
           name="End">
         <incoming>flow5</incoming>
         <incoming>flow6</incoming>
       </endEvent>
   
     </process