Activiti(5)--任意节点跳转

1. 任意节点跳转以及原理

• 常规节点跳转
  • 跳转到目标节点
  • 跳转到目标节点的入线
  • 跳转到目标节点的上一个节点并触发连线的条件计算
• 多实例节点的跳转
  • 普通节点跳转到多实例节点
  • 多实例节点跳转到普通节点

比如总经理审批节点跳转到请假申请节点:

思路:

1. 可以获取总经理审批节点对应的任务 ID, 实例 ID, 执行实例 ID
2. 可以通过 planContiuneProcessInCompensation 方法让当前执行的实例按照我们预期的效果流转
3. 我们可以将当前执行实例中的 currentFlowElement 字段设置为 请假申请 节点 XML 中的 id 值;
4. 因为执行实例运转之后, 当前的任务节点并没有被删除, 所以需要手工删除;
5. 历史表跳转之前的任务节点也不会被完成, 需要手工进行完成.

1.1. 实现方案

• 获取 ActivitiEngineAgenda
• commandContext.getExecutionEntityManager() 获取 ExecutionEntityManager
• commandContext.getTaskEntityManager() 获取 TaskEntityManager
• 设置执行实例的运行节点
• 触发执行实例运转
• 设置删除当前的任务节点
• 更新历史实例表以及历史任务表, 当前的任务节点为完成状态

@AllArgsConstructor
public class JumpCmd implements Command<Void> {

    private String taskId;
    private String targetNodeId;

    @Override
    public Void execute(CommandContext commandContext) {
        ActivitiEngineAgenda agenda = commandContext.getAgenda();
        TaskEntityManager taskEntityManager = commandContext.getTaskEntityManager();
        TaskEntity taskEntity = taskEntityManager.findById(taskId);
        // 执行实例 id
        String executionId = taskEntity.getExecutionId();
        String processDefinitionId = taskEntity.getProcessDefinitionId();
        ExecutionEntityManager executionEntityManager = commandContext.getExecutionEntityManager();
        HistoryManager historyManager = commandContext.getHistoryManager();
        // 执行实例对象
        ExecutionEntity executionEntity = executionEntityManager.findById(executionId);
        Process process = ProcessDefinitionUtil.getProcess(processDefinitionId);
        FlowElement flowElement = process.getFlowElement(targetNodeId);
        if (flowElement == null) {
            throw new RuntimeException("目标节点不存在");
        }
        // 将历史活动表更新
        historyManager.recordActivityEnd(executionEntity, "jump");
        // 设置当前流程
        executionEntity.setCurrentFlowElement(flowElement);
        // 跳转, 触发执行实例运转
        agenda.planContinueProcessInCompensation(executionEntity);
        // 从runtime 表中删除当前任务
        taskEntityManager.delete(taskId);
        // 将历史任务表更新, 历史任务标记为完成
        historyManager.recordTaskEnd(taskId, "jump");
        return null;
    }
}

1.2. 测试场景

假设有如下流程定义:

<?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"
             xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
             xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
             xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema"
             expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">

    <process id="my-process">

        <startEvent id="start"/>
        <sequenceFlow id="flow1" sourceRef="start" targetRef="userTask1"/>
        <userTask id="userTask1" name="userTask1" activiti:assignee="destiny1"/>
        <sequenceFlow id="flow2" sourceRef="userTask1" targetRef="userTask2"/>
        <userTask id="userTask2" name="userTask2" activiti:assignee="destiny2"/>
        <sequenceFlow id="flow3" sourceRef="userTask2" targetRef="end"/>
        <endEvent id="end"/>

    </process>

</definitions>

结构如下:

start -> userTask1 -> userTask2 -> end

使用如下的执行顺序:

1. startProcessInstance
2. complete 任务 userTask1
3. 执行 ManagementService().executeCommand(new JumpCmd("7502", "userTask1"))
4. complete 任务 userTask1
5. 执行 ManagementService().executeCommand(new JumpCmd("7502", "userTask1"))

然后查询 ACT_HI_ACTINST 表, 能够看到如下执行轨迹:

ID_	PROC_DEF_ID_	PROC_INST_ID_	EXECUTION_ID_	ACT_ID_	TASK_ID_	CALL_PROC_INST_ID_	ACT_NAME_	ACT_NAME_	ASSIGNEE_	START_TIME_	END_TIME_	DURATION_	DELETE_REASON_	TENANT_ID_
6	my-process:1:3	4	5	start			startEvent		2019-03-04 00:37:54.328	2019-03-04 00:37:54.330	2	“”
7	my-process:1:3	4	5	userTask1	8		userTask1	userTask	destiny1	2019-03-04 00:37:54.331	2019-03-04 00:38:19.920	25589		“”
2501	my-process:1:3	4	5	userTask2	2502		userTask2	userTask	destiny2	2019-03-04 00:38:19.933	2019-03-04 00:38:44.834	24901	jump	“”
5001	my-process:1:3	4	5	userTask1	5002		userTask1	userTask	destiny1	2019-03-04 00:38:44.848	2019-03-04 00:39:02.232	17384		“”
7501	my-process:1:3	4	5	userTask2	7502		userTask2	userTask	destiny2	2019-03-04 00:39:02.245	2019-03-04 00:39:19.718	17473	jump	“”
10001	my-process:1:3	4	5	userTask1	10002	userTask1	userTask	destiny1	2019-03-04 00:39:19.743				“”

可以看到我们已经完成了简单条件下的跳转

1.3. 关于自由跳转时历史活动不更新问题的解决

之前遇到一个错误的写法:

@AllArgsConstructor
public class JumpCmd implements Command<Void> {

    private String taskId;
    private String targetNodeId;

    @Override
    public Void execute(CommandContext commandContext) {
        ActivitiEngineAgenda agenda = commandContext.getAgenda();
        TaskEntityManager taskEntityManager = commandContext.getTaskEntityManager();
        TaskEntity taskEntity = taskEntityManager.findById(taskId);
        // 执行实例 id
        String executionId = taskEntity.getExecutionId();
        String processDefinitionId = taskEntity.getProcessDefinitionId();
        ExecutionEntityManager executionEntityManager = commandContext.getExecutionEntityManager();
        HistoryManager historyManager = commandContext.getHistoryManager();
        // 执行实例对象
        ExecutionEntity executionEntity = executionEntityManager.findById(executionId);
        Process process = ProcessDefinitionUtil.getProcess(processDefinitionId);
        FlowElement flowElement = process.getFlowElement(targetNodeId);
        if (flowElement == null) {
            throw new RuntimeException("目标节点不存在");
        }
        // 设置当前流程
        executionEntity.setCurrentFlowElement(flowElement);
        // 跳转, 触发执行实例运转
        agenda.planContinueProcessInCompensation(executionEntity);
        // 从runtime 表中删除当前任务
        taskEntityManager.delete(taskId);
        // 将历史活动表更新
        historyManager.recordActivityEnd(executionEntity, "jump");
        // 将历史任务表更新, 历史任务标记为完成
        historyManager.recordTaskEnd(taskId, "jump");
        return null;
    }
}

与上文中正确写法的不同之处在于数据库更新操作的顺序. 但仅仅更换顺序也会到导致历史表中数据无法正确结束.

问题的原因在于第 25 行的时候已经为执行实例执行了 setCurrentFlowElement() 操作, 设置了最新的流程元素, 所以如果在后面再执行对 ACT_HI_ACTINST 的更新, 就无法找到正确的 FlowElement. 所以需要将 historyManager.recordActivityEnd(executionEntity, "jump"); 放在第 25 行之前

2. 跳转到目标节点的入线

假设有如下流程定义:

<?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"
             xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
             xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
             xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema"
             expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
    <process id="my-process">
        <startEvent id="start"/>
        <userTask id="userTask1" name="userTask1" activiti:assignee="destiny1"/>
        <userTask id="userTask2" name="userTask2" activiti:assignee="destiny2"/>
        <userTask id="userTask3" name="userTask3" activiti:assignee="destiny3"/>
        <endEvent id="end1"/>
        <endEvent id="end2"/>
        <sequenceFlow sourceRef="start" targetRef="userTask1"/>
        <sequenceFlow sourceRef="userTask1" targetRef="userTask2">
            <conditionExpression>${condition==1}</conditionExpression>
        </sequenceFlow>
        <sequenceFlow sourceRef="userTask1" targetRef="userTask3">
            <conditionExpression>${condition==2}</conditionExpression>
        </sequenceFlow>
        <sequenceFlow sourceRef="userTask2" targetRef="end1"/>
        <sequenceFlow sourceRef="userTask3" targetRef="end2"/>
    </process>
</definitions>

将原先的跳转命令类稍作修改:

@AllArgsConstructor
public class SequenceFlowJumpCmd implements Command<Void> {

    private String taskId;
    private String targetNodeId;

    @Override
    public Void execute(CommandContext commandContext) {
        ActivitiEngineAgenda agenda = commandContext.getAgenda();
        TaskEntityManager taskEntityManager = commandContext.getTaskEntityManager();
        TaskEntity taskEntity = taskEntityManager.findById(taskId);
        // 执行实例 id
        String executionId = taskEntity.getExecutionId();
        String processDefinitionId = taskEntity.getProcessDefinitionId();
        ExecutionEntityManager executionEntityManager = commandContext.getExecutionEntityManager();
        HistoryManager historyManager = commandContext.getHistoryManager();
        // 执行实例对象
        ExecutionEntity executionEntity = executionEntityManager.findById(executionId);
        Process process = ProcessDefinitionUtil.getProcess(processDefinitionId);
        FlowElement flowElement = process.getFlowElement(targetNodeId);
        if (flowElement == null) {
            throw new RuntimeException("目标节点不存在");
        }
        SequenceFlow sequenceFlow = null;
        if (flowElement instanceof FlowNode) {
            FlowNode flowNode = (FlowNode) flowElement;
            // 找到所有的入线, 并取其中唯一的一条
            List<SequenceFlow> incomingFlows = flowNode.getIncomingFlows();
            sequenceFlow = incomingFlows.get(0);
        }
        if (sequenceFlow == null) {
            throw new RuntimeException("目标连线不存在");
        }
        // 将历史活动表更新
        historyManager.recordActivityEnd(executionEntity, "jump");
        // 设置当前流程
        executionEntity.setCurrentFlowElement(sequenceFlow);
        // 触发执行实例运转, 第二个参数为是否参与计算
        agenda.planTakeOutgoingSequenceFlowsOperation(executionEntity, true);
        // 从runtime 表中删除当前任务
        taskEntityManager.delete(taskId);
        // 将历史任务表更新, 历史任务标记为完成
        historyManager.recordTaskEnd(taskId, "jump");
        return null;
    }
}

• 通过连线触发实例的时候, 连线上的条件不会参与计算
• 只有实例经过节点, 网关的时候, 连线上的条件才会经过计算

3. 跳转到目标节点入线连接的节点

因为实例是从节点离开, 因此后面的连线是可以参与运算的

@AllArgsConstructor
public class SequenceFlowSourceJumpCmd implements Command<Void> {

    private String taskId;
    private String targetNodeId;
    private Map<String, Object> condition;

    @Override
    public Void execute(CommandContext commandContext) {
        ActivitiEngineAgenda agenda = commandContext.getAgenda();
        TaskEntityManager taskEntityManager = commandContext.getTaskEntityManager();
        TaskEntity taskEntity = taskEntityManager.findById(taskId);
        // 执行实例 id
        String executionId = taskEntity.getExecutionId();
        String processDefinitionId = taskEntity.getProcessDefinitionId();
        ExecutionEntityManager executionEntityManager = commandContext.getExecutionEntityManager();
        HistoryManager historyManager = commandContext.getHistoryManager();
        // 执行实例对象
        ExecutionEntity executionEntity = executionEntityManager.findById(executionId);
        Process process = ProcessDefinitionUtil.getProcess(processDefinitionId);
        FlowElement flowElement = process.getFlowElement(targetNodeId);
        if (flowElement == null) {
            throw new RuntimeException("目标节点不存在");
        }
        SequenceFlow sequenceFlow = null;
        if (flowElement instanceof FlowNode) {
            FlowNode flowNode = (FlowNode) flowElement;
            // 找到所有的入线, 并取其中唯一的一条
            List<SequenceFlow> incomingFlows = flowNode.getIncomingFlows();
            sequenceFlow = incomingFlows.get(0);
        }
        if (sequenceFlow == null) {
            throw new RuntimeException("目标连线不存在");
        }
        FlowElement sourceFlowElement = sequenceFlow.getSourceFlowElement();
        executionEntity.setVariables(condition);
        // 将历史活动表更新
        historyManager.recordActivityEnd(executionEntity, "jump");
        // 设置当前流程
        executionEntity.setCurrentFlowElement(sourceFlowElement);
        // 触发执行实例运转, 第二个参数为是否参与计算
        agenda.planTakeOutgoingSequenceFlowsOperation(executionEntity, true);
        // 从runtime 表中删除当前任务
        taskEntityManager.delete(taskId);
        // 将历史任务表更新, 历史任务标记为完成
        historyManager.recordTaskEnd(taskId, "jump");
        return null;
    }
}