Spring集成Web环境——自定义ContextLoadListener

创建ContextLoadListener类：

public class ContextLoaderListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
        //将Spring的应用上下文对象存储到ServletContext域中
        ServletContext servletContext = servletContextEvent.getServletContext();
        servletContext.setAttribute("app",app);
        System.out.println("Spring容器创建完毕。。。。。。");
    }

    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {

    }
}

并在web.xml中配置监听器

<!--配置监听器-->
    <listener>
        <listener-class>com.listener.ContextLoaderListener</listener-class>
    </listener>
    

之后在HttpServlet的继承类中就可以用

ServletContext servletContext = this.getServletContext();
WebApplicationContext webApplicationContext = WebApplicationContextUtils.getWebApplicationContext(servletContext);
UserService bean = webApplicationContext.getBean(UserService.class);

来获取注入的Bean内容