Camunda

bpmn调用过程

本部分内容使用：Camunda 7.23.0版本

pom.xml
<dependency>
    <groupId>org.camunda.bpm.springboot</groupId>
    <artifactId>camunda-bpm-spring-boot-starter</artifactId>
    <version>7.23.0</version>
</dependency>

追踪调用过程使用项目地址

启动过程

HelloProcessController
@RestController
public class HelloProcessController {

    private final RuntimeService runtimeService;
    private final TaskService taskService;
    // other codes ...
}

由于依赖了RuntimeService，触发SpringBoot自动装配Camunda相关的配置类。

信息

总配置类 org.camunda.bpm.spring.boot.starter.CamundaBpmAutoConfiguration

在 org.camunda.bpm.spring.boot.starter.CamundaBpmConfiguration 中创建ProcessEngineConfigurationImpl

⇒ org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl 主要是初始化一堆plugin

⇒ org.camunda.bpm.engine.spring.ProcessEngineFactoryBean 创建org.camunda.bpm.engine.ProcessEngine的FactoryBean，使用ProcessEngineConfigurationImpl

构建引擎 org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl#buildProcessEngine

org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl#invokePreInit

Interceptor调用链分析

org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl#getDefaultCommandInterceptorsTxRequired public abstract class CommandInterceptor implements CommandExecutor

org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl类中有一个属性 protected List<CommandInterceptor> commandInterceptorsTxRequired;, 所有这些CommandInterceptors都是CommandExecutor。

在 org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl#initCommandExecutorTxRequired Line 1586行中初始化。从后往前，把一个个Interceptor链接起来，然后将第一个赋值给commandExecutorTxRequiresNew。

ProcessEngineConfigurationImpl
/**
 * this will be initialized during the configurationComplete()
 */
protected CommandExecutor commandExecutorTxRequiresNew;
protected void initCommandExecutorTxRequired() {
  if (commandExecutorTxRequired == null) {
    commandExecutorTxRequired = initInterceptorChain(commandInterceptorsTxRequired);
  }
}
protected CommandInterceptor initInterceptorChain(List<CommandInterceptor> chain) {
  if (chain == null || chain.isEmpty()) {
    throw new ProcessEngineException("invalid command interceptor chain configuration: " + chain);
  }
  for (int i = 0; i < chain.size() - 1; i++) {
    chain.get(i).setNext(chain.get(i + 1));
  }
  return chain.get(0);
}

具体有哪些Interceptors呢？

20251011232211

初始化了哪些Service

ProcessEngineConfigurationImpl
protected RepositoryService repositoryService = new RepositoryServiceImpl();
protected RuntimeService runtimeService = new RuntimeServiceImpl();
protected HistoryService historyService = new HistoryServiceImpl();
protected IdentityService identityService = new IdentityServiceImpl();
protected TaskService taskService = new TaskServiceImpl();
protected FormService formService = new FormServiceImpl();
protected ManagementService managementService = new ManagementServiceImpl(this);
protected AuthorizationService authorizationService = new AuthorizationServiceImpl();
protected CaseService caseService = new CaseServiceImpl();
protected FilterService filterService = new FilterServiceImpl();
protected ExternalTaskService externalTaskService = new ExternalTaskServiceImpl();
protected DecisionService decisionService = new DecisionServiceImpl();
protected OptimizeService optimizeService = new OptimizeService();

如何调用这个类

反射

hello-process.bpmn
<?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:camunda="http://camunda.org/schema/1.0/bpmn"
             targetNamespace="Examples">
  <process id="helloProcess"
           name="Hello Process"
           isExecutable="true"
           camunda:historyTimeToLive="180">
    <startEvent id="StartEvent_1" />
    <sequenceFlow id="flow1" sourceRef="StartEvent_1" targetRef="ServiceTask_1"/>
    <serviceTask id="ServiceTask_1"
                 name="Say Hello"
                 camunda:class="com.example.camunda.delegate.HelloDelegate" />
    <sequenceFlow id="flow2" sourceRef="ServiceTask_1" targetRef="UserTask_1"/>
    <userTask id="UserTask_1" name="审批一下" />
    <sequenceFlow id="flow3" sourceRef="UserTask_1" targetRef="EndEvent_1"/>
    <endEvent id="EndEvent_1" />

  </process>
</definitions>

@Slf4j
public class HelloDelegate implements JavaDelegate {
    @Override
    public void execute(DelegateExecution execution) {
        log.info("Hello from Camunda Delegate! processInstanceId={}", execution.getProcessInstanceId());
        execution.setVariable("greeting", "hello from delegate");
    }
}

camunda:class="com.example.camunda.delegate.HelloDelegate" 表明了通过反射调用，真实调用代码位置 ClassDelegateActivityBehavior#getActivityBehaviorInstance(ActivityExecution)

通过spring容器

delegateExpression: 适合需要实现 JavaDelegate 接口的场景,更符合 Camunda 规范 camunda:delegateExpression="${helloDelegate}"

delegateExpression

hello-process.bpmn
<?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:camunda="http://camunda.org/schema/1.0/bpmn"
             targetNamespace="Examples">
  <process id="helloProcess"
           name="Hello Process"
           isExecutable="true"
           camunda:historyTimeToLive="180">
    <startEvent id="StartEvent_1" />
    <sequenceFlow id="flow1" sourceRef="StartEvent_1" targetRef="ServiceTask_1"/>
    <serviceTask id="ServiceTask_1"
                 name="Say Hello"
                 camunda:delegateExpression="${helloDelegate}" />
    <sequenceFlow id="flow2" sourceRef="ServiceTask_1" targetRef="UserTask_1"/>
    <userTask id="UserTask_1" name="审批一下" />
    <sequenceFlow id="flow3" sourceRef="UserTask_1" targetRef="EndEvent_1"/>
    <endEvent id="EndEvent_1" />

  </process>
</definitions>

HelloDelegate
@Slf4j
@Component
public class HelloDelegate implements JavaDelegate {
    @Override
    public void execute(DelegateExecution execution) {
        log.info("Hello from Camunda Delegate! processInstanceId={}", execution.getProcessInstanceId());
        execution.setVariable("greeting", "hello from delegate");
    }
}

expression: 更灵活,可以直接调用 Spring Bean 的任意方法,不需要实现特定接口 camunda:expression="${helloDelegate1.sayHello(execution)}

expression方式

hello-process.bpmn
<?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:camunda="http://camunda.org/schema/1.0/bpmn"
             targetNamespace="Examples">

  <process id="helloProcess"
           name="Hello Process"
           isExecutable="true"
           camunda:historyTimeToLive="180">
    <startEvent id="StartEvent_1" />
    <sequenceFlow id="flow1" sourceRef="StartEvent_1" targetRef="ServiceTask_1"/>
    <serviceTask id="ServiceTask_1"
                 name="Say Hello"
                 camunda:expression="${helloDelegate1.sayHello(execution)}" />
    <sequenceFlow id="flow2" sourceRef="ServiceTask_1" targetRef="UserTask_1"/>
    <userTask id="UserTask_1" name="审批一下" />
    <sequenceFlow id="flow3" sourceRef="UserTask_1" targetRef="EndEvent_1"/>
    <endEvent id="EndEvent_1" />
  </process>
</definitions>

@Component title="HelloDelegate1"
public class HelloDelegate1 {
    private static final Logger log = LoggerFactory.getLogger(HelloDelegate1.class);
    public void sayHello(DelegateExecution execution) {
        // 使用注入的服务
        log.info("Hello from Camunda Delegate! processInstanceId={}", execution.getProcessInstanceId());
        execution.setVariable("greeting1", "hello from delegate");
    }
}

奇怪的debug手段

比如想在jar包中的AbstractEventAtomicOperation第50行打印控制台日志。

使用condition debug并且取消suspend。

界面效果如下:

System.out.println(String.format("[%s] %s", ((org.camunda.bpm.engine.impl.pvm.runtime.PvmExecutionImpl)execution).getCurrentActivityId(), this.getClass().getSimpleName())) == null

20251012001135

状态机状态转化过程

performOperation(CoreAtomicOperation):609, ExecutionEntity (org.camunda.bpm.engine.impl.persistence.entity), ExecutionEntity.java
callback(PvmExecutionImpl):75, PvmAtomicOperationProcessStart$2 (org.camunda.bpm.engine.impl.pvm.runtime.operation), PvmAtomicOperationProcessStart.java
callback(Object):70, PvmAtomicOperationProcessStart$2 (org.camunda.bpm.engine.impl.pvm.runtime.operation), PvmAtomicOperationProcessStart.java
continueIfExecutionDoesNotAffectNextOperation(Callback, Callback, PvmExecutionImpl):2109, PvmExecutionImpl (org.camunda.bpm.engine.impl.pvm.runtime), PvmExecutionImpl.java
eventNotificationsCompleted(PvmExecutionImpl):64, PvmAtomicOperationProcessStart (org.camunda.bpm.engine.impl.pvm.runtime.operation), PvmAtomicOperationProcessStart.java
eventNotificationsCompleted(CoreExecution):30, PvmAtomicOperationProcessStart (org.camunda.bpm.engine.impl.pvm.runtime.operation), PvmAtomicOperationProcessStart.java
execute(CoreExecution):70, AbstractEventAtomicOperation (org.camunda.bpm.engine.impl.core.operation), AbstractEventAtomicOperation.
execute(BpmnStackTrace, ProcessDataContext):99, AtomicOperationInvocation (org.camunda.bpm.engine.impl.interceptor), AtomicOperationInvocation.java
invokeNext():141, CommandInvocationContext (org.camunda.bpm.engine.impl.interceptor), CommandInvocationContext.java
performNext():128, CommandInvocationContext (org.camunda.bpm.engine.impl.interceptor), CommandInvocationContext.java
performOperation(AtomicOperation, ExecutionEntity, boolean):96, CommandInvocationContext (org.camunda.bpm.engine.impl.interceptor), CommandInvocationContext.java [1]
performOperation(AtomicOperation):635, ExecutionEntity (org.camunda.bpm.engine.impl.persistence.entity), ExecutionEntity.java
performOperation(CoreAtomicOperation):609, ExecutionEntity (org.camunda.bpm.engine.impl.persistence.entity), ExecutionEntity.java
start(Map, VariableMap):294, PvmExecutionImpl (org.camunda.bpm.engine.impl.pvm.runtime), PvmExecutionImpl.java

start-hello task

Controler接口

package com.example.camunda.web;

import org.camunda.bpm.engine.RuntimeService;
import org.camunda.bpm.engine.TaskService;
import org.camunda.bpm.engine.runtime.ProcessInstance;
import org.camunda.bpm.engine.task.Task;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class HelloProcessController {

    private final RuntimeService runtimeService;
    private final TaskService taskService;

    public HelloProcessController(RuntimeService runtimeService, TaskService taskService) {
        this.runtimeService = runtimeService;
        this.taskService = taskService;
    }

    // 启动流程
    @GetMapping("/start-hello")
    public String startHelloProcess() {
        ProcessInstance instance = runtimeService.startProcessInstanceByKey("helloProcess");
        return "流程启动成功，实例ID: " + instance.getId();
    }

    // 查询当前待办任务
    @GetMapping("/tasks")
    public String listTasks() {
        List<Task> tasks = taskService.createTaskQuery().list();
        if (tasks.isEmpty()) {
            return "当前没有待办任务";
        }
        StringBuilder sb = new StringBuilder("待办任务列表：\n");
        for (Task task : tasks) {
            sb.append("任务ID=").append(task.getId())
              .append(", 名称=").append(task.getName())
              .append(", 流程实例ID=").append(task.getProcessInstanceId())
              .append("\n");
        }
        return sb.toString();
    }

    // 完成任务
    @PostMapping("/complete/{taskId}")
    public String completeTask(@PathVariable String taskId) {
        taskService.complete(taskId);
        return "任务已完成: " + taskId;
    }
}

GET http://localhost:8080/start-hello

在 org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity#performOperation(org.camunda.bpm.engine.impl.core.operation.CoreAtomicOperation<T>)
处使用条件断点,断点打印信息如下

System.out.println(String.format("[ActivityId: %s] Operation: %s, Thread: %s", 
    this.activityId != null ? this.activityId : "ROOT",
    operation.getClass().getSimpleName(),
    Thread.currentThread().getName())) == null

start-hello 去重之后的日志
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationProcessStart, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationActivityStartCreateScope, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationActivityStart, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationActivityExecute, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationActivityLeave, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationTransitionNotifyListenerEnd, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationTransitionDestroyScope, Thread: http-nio-8080-exec-7
[ActivityId: StartEvent_1] Operation: PvmAtomicOperationTransitionNotifyListenerTake, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationTransitionCreateScope, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerStart, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationActivityExecute, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationActivityLeave, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerEnd, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationTransitionDestroyScope, Thread: http-nio-8080-exec-7
[ActivityId: ServiceTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerTake, Thread: http-nio-8080-exec-7
[ActivityId: UserTask_1] Operation: PvmAtomicOperationTransitionCreateScope, Thread: http-nio-8080-exec-7
[ActivityId: UserTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerStart, Thread: http-nio-8080-exec-7
[ActivityId: UserTask_1] Operation: PvmAtomicOperationActivityExecute, Thread: http-nio-8080-exec-7

complete task

POST http://localhost:8080/complete/55e03f1c-a5f7-11f0-9020-b05cda36f80c
Content-Type: application/x-www-form-urlencoded

complete 去重之后的日志
[ActivityId: UserTask_1] Operation: PvmAtomicOperationActivityLeave, Thread: http-nio-8080-exec-10
[ActivityId: UserTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerEnd, Thread: http-nio-8080-exec-10
[ActivityId: UserTask_1] Operation: PvmAtomicOperationTransitionDestroyScope, Thread: http-nio-8080-exec-10
[ActivityId: UserTask_1] Operation: PvmAtomicOperationTransitionNotifyListenerTake, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationTransitionCreateScope, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationTransitionNotifyListenerStart, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationActivityExecute, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationActivityNotifyListenerEnd, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationActivityEnd, Thread: http-nio-8080-exec-10
[ActivityId: EndEvent_1] Operation: PvmAtomicOperationProcessEnd, Thread: http-nio-8080-exec-10

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bpmn调用过程​

启动过程​

Interceptor调用链分析​

初始化了哪些Service​

如何调用这个类​

反射​

通过spring容器​

奇怪的debug手段​

状态机状态转化过程​

start-hello task​

complete task​