/**
   * @author 郑小康
   * 流程引擎配置共有七种方法
   * 方法1 方法2调用的实际是方法3
   * 方法4 调用其实就是方法5
   * 方法6 和方法7是相同
   * */

  //方法1
  //实际调用的方法三只不过默认beanName是processEngineConfiguration，resource为activiti.cfg.xml
  public static ProcessEngineConfiguration createProcessEngineConfigurationFromResourceDefault() {
    return createProcessEngineConfigurationFromResource("activiti.cfg.xml", "processEngineConfiguration");
  }

  //方法2
  public static ProcessEngineConfiguration createProcessEngineConfigurationFromResource(String resource) {
    return createProcessEngineConfigurationFromResource(resource, "processEngineConfiguration");
  }

  //方法3
  //主要实现过程获取资源位置路径,以及beanName来获取对应的ProcessEngineConfiguration实例
  public static ProcessEngineConfiguration createProcessEngineConfigurationFromResource(String resource, String beanName) {
    return BeansConfigurationHelper.parseProcessEngineConfigurationFromResource(resource, beanName);
  }

  //方法4
  public static ProcessEngineConfiguration createProcessEngineConfigurationFromInputStream(InputStream inputStream) {
    return createProcessEngineConfigurationFromInputStream(inputStream, "processEngineConfiguration");
  }

  //方法5
  //同方法一二三相同，只不过是以文件流来创建ProcessEngineConfiguration实例
  public static ProcessEngineConfiguration createProcessEngineConfigurationFromInputStream(InputStream inputStream, String beanName) {
    return BeansConfigurationHelper.parseProcessEngineConfigurationFromInputStream(inputStream, beanName);
  }

  //方法6
  //创建一个实例,在即再手动注入数据库相关属性通过其父类ProcessEngineConfigurationImpl来进行实现
  public static ProcessEngineConfiguration createStandaloneProcessEngineConfiguration() {
    return new StandaloneProcessEngineConfiguration();
  }

  //方法7
  //继承了StandaloneProcessEngineConfiguration,只是在这个基础上设置了 databaseSchemaUpdate的属性和jdbcUrl
  public static ProcessEngineConfiguration createStandaloneInMemProcessEngineConfiguration() {
    return new StandaloneInMemProcessEngineConfiguration();
  }

<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-study?useUnicode=true&characterEncoding=UTF-8
			</value>
		</property>
		<property name="username">
			<value>root</value>
		</property>
		<property name="password" value="" />
	</bean>

	<bean id="processEngineConfigurationxQ"
		class="org.activiti.engine.impl.cfg.StandaloneProcessEngineConfiguration">
		<property name="dataSource" ref="dataSource" />
		<property name="databaseSchemaUpdate" value="true" />
	</bean>

</beans>

private final String cfgXml =  System.getProperty("user.dir") + "/activiti/config/activiti.cfg.xml";
	//方法1 2 3 的实现方式
	@Test
	public void createProcessEngineConfigurationFromResource() {
		ProcessEngineConfiguration processEngineConfiguration = ProcessEngineConfiguration.createProcessEngineConfigurationFromResource(cfgXml);
		System.out.println(processEngineConfiguration);
		ProcessEngine processEngine=processEngineConfiguration.buildProcessEngine();
		System.out.println(processEngine);

		processEngineConfiguration =ProcessEngineConfiguration.createProcessEngineConfigurationFromResource(cfgXml,"processEngineConfiguration");
		System.out.println(processEngineConfiguration);
		processEngine=processEngineConfiguration.buildProcessEngine();
		System.out.println(processEngine);
	}

	//方法4 和 5实现的方法方式
	@Test
	public void createProcessEngineConfigurationFromInputStream() throws IOException {
		InputStream in = new FileInputStream(cfgXml);
		ProcessEngineConfiguration configurationFromInputStream = ProcessEngineConfiguration
				.createProcessEngineConfigurationFromInputStream(in);
		System.out.println(configurationFromInputStream);
	}

	//方法6 和 7实现的方式
	@Test
	public void createStandaloneInMemProcessEngineConfiguration() {
		ProcessEngineConfiguration pec = ProcessEngineConfiguration
				.createStandaloneInMemProcessEngineConfiguration();
		pec.setJdbcDriver("com.mysql.jdbc.Driver");
		pec.setJdbcUrl("jdbc:mysql://127.0.0.1:3306/activiti-study?useUnicode=true&characterEncoding=UTF-8");
		pec.setJdbcUsername("root");
		pec.setJdbcPassword("");
		System.out.println(pec);
	}