如何让spring mvc web应用启动时就执行特定处理

Asp.Net的应用中通过根目录下的Global.asax，在Application_Start方法中做一些初始化操作，比如：预先加载缓存项对网站热点数据进行预热，获取一些远程的配置信息等等。
Spring-MVC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 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。

在web服务启动时把从数据库读取到的数据放到ServletContext中

这个是一个项目中的Controller，目的是将数据库中的音乐分类信息在服务器启动的时候读取到ServletContext中

框架：spring，spring mvc,mybatis

package com.zhangjinbang.web;

import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.context.ServletContextAware;

import com.zhangjinbang.dao.MusicTypeMapper;
import com.zhangjinbang.model.MusicType;
import com.zhangjinbang.model.MusicTypeExample;

@Controller
@RequestMapping("/")
public class SlumberController implements ServletContextAware{

private MusicTypeMapper musicTypeMapper;

@Autowired
public SlumberController(MusicTypeMapper musicTypeMapper) {
super();
this.musicTypeMapper = musicTypeMapper;

}

@RequestMapping({"","home"})
public String home(){
return "index";
}

//加载分类信息
@RequestMapping("start")
public String asmr(HttpServletRequest request){

ServletContext application = request.getServletContext();
@SuppressWarnings("unchecked")
List<MusicType> musicTypeList=(List<MusicType>)application.getAttribute("musicTypeList");
return "forward:/music/"+musicTypeList.get(0).getId();
}

public void setServletContext(ServletContext servletContext) {
MusicTypeExample example=new MusicTypeExample();
List<MusicType> musicTypeList=musicTypeMapper.selectByExample(example);
servletContext.setAttribute("musicTypeList", musicTypeList);
}
}

参考

《如何让spring mvc web应用启动时就执行特定处理 》菩提树下的杨过.Net