spring mvc web应用启动时执行特定处理

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

Spring-MVC的应用中，要实现 web应用启动时执行特定处理，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

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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

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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

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package org.springframework.beans.factory;
 
public interface InitializingBean {
     void afterPropertiesSet() throws Exception;
}

四、ApplicationListener<ApplicationEvent> 接口

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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：

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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。

 


posted @ 2016-12-28 08:51  hongweigg  阅读(9)  评论(0)    收藏  举报