转载：如何让spring mvc web应用启动时就执行

http://www.cnblogs.com/yjmyzz/p/4747251.html#

Spring-MVC的应用中

一、ApplicationContextAware接口

package org.springframework.context;

import org.springframework.beans.BeansException;

import org.springframework.beans.factory.Aware;

import org.springframework.context.ApplicationContext;

public interface ApplicationContextAware extends Aware {

    void setApplicationContext(ApplicationContext var1) throws BeansException;

}

二、ServletContextAware 接口

package org.springframework.web.context;

import javax.servlet.ServletContext;

import org.springframework.beans.factory.Aware;

public interface ServletContextAware extends Aware {

    void setServletContext(ServletContext var1);

}

三、InitializingBean 接口

package org.springframework.beans.factory;

public interface InitializingBean {

    void afterPropertiesSet() throws Exception;

}

四、ApplicationListener<ApplicationEvent> 接口

package org.springframework.context;

import java.util.EventListener;

import org.springframework.context.ApplicationEvent;

public interface ApplicationListener<E extends ApplicationEvent> extends EventListener {

    void onApplicationEvent(E var1);

}

示例程序：

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

注意：onApplicationEvent方法会触发多次，初始化这种事情，越早越好，建议在setApplicationContext方法中处理。