Spring 的 ApplicationEvent and ApplicationListener 、spring框架加载完成后执行上下文刷新事件(ContextRefreshedEvent)

ApplicationContext在运行期会自动检测到所有实现了ApplicationListener的bean对象，并将其作为事件接收对象。当ApplicationContext的publishEvent方法被触发时，每个实现了ApplicationListener接口的bean都会收到ApplicationEvent对象，每个ApplicationListener可根据事件类型只接收处理自己感兴趣的事件，比如上面的StudentAddListener只接收StudentAddEvent事件。

http://blog.csdn.net/liuwenbo0920/article/details/7263766（非常好）

http://yangyongbyjava.iteye.com/blog/1600581

http://www.th7.cn/Program/java/201408/271385.shtml（ApplicationListener接口中的onApplicationEvent被调用两次解决方案）

Spring监听 ApplicationListener

import java.util.HashMap;import java.util.Map;import org.apache.commons.lang3.StringUtils;import org.apache.log4j.Logger;importorg.springframework.beans.factory.annotation.Autowired;importorg.springframework.beans.factory.annotation.Qualifier;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationListener;importorg.springframework.context.event.ContextRefreshedEvent;import org.springframework.stereotype.Component;@Componentpublic class InitDataListener implements  ApplicationListener { //ContextRefreshedEvent为初始化完毕事件 private static final Logger LOGGER =Logger   .getLogger(InitDataListener.class); // 缓存管理器 @Autowired @Qualifier("dictCacheManager") private DictCacheManager dictCacheManager; @Override public voidonApplicationEvent(ContextRefreshedEvent event) {  final ApplicationContext app= event.getApplicationContext();  if (null ==app.getParent()    &&"Root WebApplicationContext".equals(app.getDisplayName())) { //当存在父子容器时，此判断很有用   //读取字典配置   Map config =new HashMap();   try {    config= PathUtil.getProperties("dataDictConfig.properties");    finalString mKey = config.get("dataDictKey");    if(StringUtils.isNotBlank(mKey)) {     DictCacheManager.M_KEY= mKey;    }   } catch(Exception e) {    LOGGER.error("Load\"dataDictConfig.properties\" failure!", e);   }   //判断是否立即加载数据字典到Redis   if("false".equals(config.get("lazyLoad"))) { //立即加载数据字典数据到Redis缓存服务器    dictCacheManager.init();   }  } }}}