activiti学习笔记(三) 监听生命周期

activiti监听生命周期

activiti生命周期的作用

生命周期的作用是在构建processEngine实例时候或者关闭的时候调用对应处理方法,比如我在启动实例的时候，可以对实例做一些预处理

activiti的接口类

public interface ProcessEngineLifecycleListener {  /**实体引擎实例化的时候调用该方法*/  void onProcessEngineBuilt(ProcessEngine processEngine);  /**实体引擎关闭的时候调用该方法*/  void onProcessEngineClosed(ProcessEngine processEngine);}

activiti的生命周期的实现

       首先通过bean进行实例化，再注入到当前bean，具体监听则是在构建实例和关闭实例的时候

   构建实例：会调用监听类的onProcessEngineBuilt方法

  /**   * @author 郑小康   *   * 1.注入流程配置实例的一些变量到当前实例   *   * 2.FIXME:未知   *   * 3.注册当前流程实例   *   * 4.FIXME:未知   *   * 5.调用监听方法，这也是这里需要描述的核心（不是本方法的核心）   * */  public ProcessEngineImpl(ProcessEngineConfigurationImpl processEngineConfiguration) {    this.processEngineConfiguration = processEngineConfiguration;    this.name = processEngineConfiguration.getProcessEngineName();    this.repositoryService = processEngineConfiguration.getRepositoryService();    this.runtimeService = processEngineConfiguration.getRuntimeService();    this.historicDataService = processEngineConfiguration.getHistoryService();    this.identityService = processEngineConfiguration.getIdentityService();    this.taskService = processEngineConfiguration.getTaskService();    this.formService = processEngineConfiguration.getFormService();    this.managementService = processEngineConfiguration.getManagementService();    this.dynamicBpmnService = processEngineConfiguration.getDynamicBpmnService();    this.asyncExecutor = processEngineConfiguration.getAsyncExecutor();    this.commandExecutor = processEngineConfiguration.getCommandExecutor();    this.sessionFactories = processEngineConfiguration.getSessionFactories();    this.transactionContextFactory = processEngineConfiguration.getTransactionContextFactory();    this.formEngineRepositoryService = processEngineConfiguration.getFormEngineRepositoryService();    this.formEngineFormService = processEngineConfiguration.getFormEngineFormService();    if (processEngineConfiguration.isUsingRelationalDatabase() && processEngineConfiguration.getDatabaseSchemaUpdate() != null) {      commandExecutor.execute(processEngineConfiguration.getSchemaCommandConfig(), new SchemaOperationsProcessEngineBuild());    }    if (name == null) {      log.info("default activiti ProcessEngine created");    } else {      log.info("ProcessEngine {} created", name);    }    ProcessEngines.registerProcessEngine(this);    if (asyncExecutor != null && asyncExecutor.isAutoActivate()) {      asyncExecutor.start();    }    //流程引擎实例化监听方法    if (processEngineConfiguration.getProcessEngineLifecycleListener() != null) {      processEngineConfiguration.getProcessEngineLifecycleListener().onProcessEngineBuilt(this);    }    processEngineConfiguration.getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createGlobalEvent(ActivitiEventType.ENGINE_CREATED));  }

   关闭实例会调用onProcessEngineClosed方法

 public void close() {    ProcessEngines.unregister(this);    if (asyncExecutor != null && asyncExecutor.isActive()) {      asyncExecutor.shutdown();    }    commandExecutor.execute(processEngineConfiguration.getSchemaCommandConfig(), new SchemaOperationProcessEngineClose());    //流程引擎关闭触发监听方法    if (processEngineConfiguration.getProcessEngineLifecycleListener() != null) {      processEngineConfiguration.getProcessEngineLifecycleListener().onProcessEngineClosed(this);    }        processEngineConfiguration.getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createGlobalEvent(ActivitiEventType.ENGINE_CLOSED));  }

activiti生命周期的使用

上面是生命周期的源码实现介绍,下面就讲述一下怎样使用

第一步：实现ProcessEngineLifecycleListener这个接口

public class processEngineLifecycleListener implements ProcessEngineLifecycleListener{public void onProcessEngineBuilt(ProcessEngine processEngine) {System.out.println("流程引擎生命周期监听器开始了....");ProcessEngineConfiguration pec = processEngine.getProcessEngineConfiguration();String activityFontName = pec.getActivityFontName();System.out.println(activityFontName);}public void onProcessEngineClosed(ProcessEngine processEngine) {}}

第二步：配置当前processEngineLifecycleListener这个bean并将其注入processEngineConfiguration里面

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beans          http://www.springframework.org/schema/beans/spring-beans.xsd"><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"><property name="driverClassName"><value>com.mysql.jdbc.Driver</value></property><property name="url"><value>jdbc:mysql://127.0.0.1:3306/activiti?useUnicode=true&characterEncoding=UTF-8</value></property><property name="username"><value>root</value></property><property name="password" value="fadp" /></bean><bean id="processEngineLifecycleListener"class="com.activiti_study.ch6.processEngineLifecycleListener"></bean><bean id="processEngine1" name="processEngineConfiguration"class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration"><property name="dataSource" ref="dataSource" /><property name="databaseSchemaUpdate" value="true" /><property name="processEngineLifecycleListener" ref="processEngineLifecycleListener"></property></bean></beans>

第三步：具体实现

      

        @Testpublic void getDefaultProcessEngine() throws FileNotFoundException {ProcessEngineConfiguration processEngineConfiguration = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource("com/activiti_study/ch6/activiti1.cfg.xml","processEngineConfiguration");ProcessEngine pe = processEngineConfiguration.buildProcessEngine();System.out.println(pe+"========");}

流程引擎生命周期监听器开始了....Arialorg.activiti.engine.impl.ProcessEngineImpl@4b29d1d2========

      从显示结果可以看出在调用buildProcessEngine方法的时候调用了ProcessEngineLifecycleListener继承类的onProcessEngineBuilt方法