class org.springframework.context.support.PropertySourcesPlaceholderConfigurer
该类实现了的接口:
1、org.springframework.beans.factory.BeanNameAware setBeanName(String name)
2、org.springframework.beans.factory.BeanFactoryAware setBeanFactory(BeanFactory beanFactory)
3、org.springframework.beans.factory.config.BeanFactoryPostProcessor postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
4、org.springframework.core.Ordered int getOrder();