Spring属性占位符PropertyPlaceholderConfigurer的使用

package com.zsw.config; import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer; import org.springframework.beans.factory.xml.XmlBeanFactory; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import org.springframework.core.io.FileSystemResource; import org.springframework.jdbc.datasource.DriverManagerDataSource; public class Config { public static void main(String[] args) { XmlBeanFactory factory = new XmlBeanFactory(new FileSystemResource("src/com/zsw/config/conf.xml")); // 如果要在BeanFactory中使用，bean factory post-processor必须手动运行: PropertyPlaceholderConfigurer cfg = new PropertyPlaceholderConfigurer(); cfg.setLocation(new FileSystemResource("src/com/zsw/config/jdbc.properties")); cfg.postProcessBeanFactory(factory); DriverManagerDataSource dataSource = (DriverManagerDataSource) factory.getBean("dataSource"); // System.out.println(dataSource.getDriverClassName()); System.out.println(dataSource.getUsername()); // 注意，ApplicationContext能够自动辨认和应用在其上部署的实现了BeanFactoryPostProcessor的bean。这就意味着，当使用ApplicationContext的时候应用PropertyPlaceholderConfigurer会非常的方便。由于这个原因，建议想要使用这个或者其他bean // factory postprocessor的用户使用ApplicationContext代替BeanFactroy。 ApplicationContext context = new ClassPathXmlApplicationContext("com/zsw/config/conf.xml"); DriverManagerDataSource dataSource2 = (DriverManagerDataSource) context.getBean("dataSource"); System.out.println(dataSource2.getUsername()); } }