/** 
 * @Description: TODO(用于项目启动的时候数据初始化) 
 * @author eson_15 
 * 
 */ 
//@Component //监听器是web层的组件，它是tomcat实例化的，不是Spring实例化的。不能放到Spring中 
public class InitDataListener implements ServletContextListener { 
 
 private ProductService productService = null;//productService中定义了跟商品相关的业务逻辑 
 
 @Override 
 public void contextDestroyed(ServletContextEvent event) { 
 
 } 
 
 @Override 
 public void contextInitialized(ServletContextEvent event) { 
 
 } 
 
} 

//@Component //监听器是web层的组件，它是tomcat实例化的，不是Spring实例化的。不能放到Spring中 
public class InitDataListener implements ServletContextListener { 
 
 
 private ProductService productService = null; //productService中定义了跟商品相关的业务逻辑 
 
 @Override 
 public void contextDestroyed(ServletContextEvent event) { 
 
 } 
 
 @Override 
 public void contextInitialized(ServletContextEvent event) { 
 // 获取业务逻辑类productService查询商品信息 
 ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml"); 
 productService = (ProductService) context.getBean("productService"); 
 System.out.println(productService); //输出看看拿到了没有 
 
 //下面是具体productService相关操作…… 
 } 
 
} 

<context-param> 
 <param-name>contextConfigLocation</param-name> 
 <!--CONFIG_LOCATION_PARM就是contextConfigLocation--> 
 <param-value>classpath:beans.xml</param-value> 
</context-param> 

//@Component //监听器是web层的组件，它是tomcat实例化的，不是Spring实例化的。不能放到Spring中 
public class InitDataListener implements ServletContextListener { 
 
 
 private ProductService productService = null; 
 
 @Override 
 public void contextDestroyed(ServletContextEvent event) { 
 // TODO Auto-generated method stub 
 
 } 
 
 @Override 
 public void contextInitialized(ServletContextEvent event) { 
 // 获取业务逻辑类查询商品信息 
 
 // 解决方案二，项目在启动时，把Spring配置文件通过Spring的监听器加载，存储到ServletContext中，我们只要在ServletContext中获取即可。 
 ApplicationContext context = (ApplicationContext) event.getServletContext() 
  .getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE); 
 productService = (ProductService) context.getBean("productService"); 
 System.out.println(productService); 
 } 
 
} 

public class InitDataListener implements ServletContextListener { 
 
 
 private ProductService productService = null; 
 
 @Override 
 public void contextDestroyed(ServletContextEvent event) { 
 // TODO Auto-generated method stub 
 
 } 
 
 @Override 
 public void contextInitialized(ServletContextEvent event) { 
 // 获取业务逻辑类查询商品信息 
 
 WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(event.getServletContext()); 
 productService = (ProductService) context.getBean("productService"); 
 System.out.println(productService); 
 } 
 
} 

public static WebApplicationContext getWebApplicationContext(ServletContext sc) { 
 return getWebApplicationContext(sc, WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE); 
 }