springmvc系统启动自动执行任务

一时失言乱红尘 2022-03-31 09:23 363阅读 0赞

<context:component-scan base-package="**.listener" />

在springmvc中配置扫描包

在该包下创建一个相关类

package test.web.listener;
     
    import org.apache.logging.log4j.*;
    import org.springframework.beans.*;
    import org.springframework.beans.factory.InitializingBean;
    import org.springframework.context.*;
    import org.springframework.context.event.ContextRefreshedEvent;
    import org.springframework.stereotype.Component;
    import org.springframework.web.context.ServletContextAware;
    import javax.servlet.ServletContext;
     
    @Component
    public class StartupListener implements ApplicationContextAware, ServletContextAware,
            InitializingBean, ApplicationListener<ContextRefreshedEvent> {
     
        protected Logger logger = LogManager.getLogger();
     
        @Override
        public void setApplicationContext(ApplicationContext ctx) throws BeansException {
            logger.info("1 => StartupListener.setApplicationContext");
        }
     
        @Override
        public void setServletContext(ServletContext context) {
            logger.info("2 => StartupListener.setServletContext");
        }
     
        @Override
        public void afterPropertiesSet() throws Exception {
            logger.info("3 => StartupListener.afterPropertiesSet");
        }
     
        @Override
        public void onApplicationEvent(ContextRefreshedEvent evt) {
            logger.info("4.1 => MyApplicationListener.onApplicationEvent");
            if (evt.getApplicationContext().getParent() == null) {
                logger.info("4.2 => MyApplicationListener.onApplicationEvent");
            }
        }
     
    }

运行时，输出的顺序如下：

*1 => StartupListener.setApplicationContext*  
*2 => StartupListener.setServletContext*  
*3 => StartupListener.afterPropertiesSet*  
*4.1 => MyApplicationListener.onApplicationEvent*  
*4.2 => MyApplicationListener.onApplicationEvent*  
*4.1 => MyApplicationListener.onApplicationEvent*