Spring MVC启动时初始化的几个常用方法

SpringMVC的应用中，要实现类似的功能，主要是通过实现下面这些接口（任选一，至少一个即可）

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 com.bijian.study.controller;

import javax.servlet.ServletContext;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Component;
import org.springframework.web.context.ServletContextAware;
 
@Component
public class StartupListener implements ApplicationContextAware, ServletContextAware,
        InitializingBean, ApplicationListener<ContextRefreshedEvent> {
 
    private 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");
        }
    }
}

服务启动时，输出的顺序如下：

22:54:44.433 [localhost-startStop-1] INFO  com.bijian.study.controller.StartupListener - 1 => StartupListener.setApplicationContext
22:54:44.435 [localhost-startStop-1] INFO  com.bijian.study.controller.StartupListener - 2 => StartupListener.setServletContext
22:54:44.435 [localhost-startStop-1] INFO  com.bijian.study.controller.StartupListener - 3 => StartupListener.afterPropertiesSet
22:54:44.931 [localhost-startStop-1] INFO  com.bijian.study.controller.StartupListener - 4.1 => MyApplicationListener.onApplicationEvent
22:54:44.931 [localhost-startStop-1] INFO  com.bijian.study.controller.StartupListener - 4.2 => 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，完整示例见附件。

此外还有一种方法：写个BEAN，将要执行的操作写在构造函数里，再将这个类配置到XML里，比如配置到SPRING-MVC.XML里 <bean class="com.test.xx"> 自己的类。不过不推荐使用这种方法。

文章来源：http://www.cnblogs.com/xiohao/p/5279581.html

参考文章：http://blog.csdn.net/axwolfer/article/details/40718609

Spring MVC启动时初始化的几个常用方法

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