Activiti流程引擎对象及配置原理解析

<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:tx="http://www.springframework.org/schema/tx"
  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
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">

  <!-- 配置使用默认bean名称的流程引擎配置对象 -->
  <bean id="processEngineConfiguration"
    class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">
    <property name="jdbcDriver" value="com.mysql.jdbc.Driver"></property>
    <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/activiti_01"></property>
    <property name="jdbcUsername" value="root"></property>
    <property name="jdbcPassword" value="root"></property>
    <property name="databaseSchemaUpdate" value="true"></property>
  </bean>

</beans>

<!-- 配置连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
  <property name="driverClass" value="com.mysql.jdbc.Driver"/>
  <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/activiti_01"/>
  <property name="user" value="root"/>
  <property name="password" value="root"/>
</bean>

  /**
   * 用ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault()
   * 创建流程引擎配置对象
   */
  @Test
  public void test1() {
    ProcessEngineConfiguration configuration = ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault();
    System.out.println(configuration);
  }

  @Test
  public void test2() {
    ProcessEngineConfiguration configuration = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource("cfg/activiti-cfg.xml", "processEngineConfiguration");
    System.out.println(configuration);
  }

  @Test
  public void testCreateProcessEngine() {
    ProcessEngineConfiguration configuration = ProcessEngineConfiguration.createProcessEngineConfigurationFromResourceDefault();
    ProcessEngine processEngine = configuration.buildProcessEngine();
    System.out.println(processEngine);
  }

  @Test
  public void testCreateProcessEngine2() {
    //读取配置文件，创建流程引擎对象缓存到map中
    ProcessEngines.init();
    //获取map
    Map<String, ProcessEngine> enginesMap = ProcessEngines.getProcessEngines();
    //获取key为default的对象
    ProcessEngine processEngine = enginesMap.get("default");
    System.out.println(processEngine);
  }

  @Test
  public void testCreateProcessEngine3() {
    ProcessEngine defaultProcessEngine = ProcessEngines.getDefaultProcessEngine();
    System.out.println(defaultProcessEngine);
  }