spring配置扫描多个包问题解析

 <!-- 自动扫描该包，使 SpringMVC 为包下用了@controller注解的类是控制器 -->

 package com.weixiao.listener; import javax.servlet.ServletContext; import org.apache.log4j.LogManager; import org.apache.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("StartupListener") public class StartupListener implements ApplicationContextAware, ServletContextAware, InitializingBean, ApplicationListener { protected Logger logger = LogManager.getLogger(getClass()); @Override public void setApplicationContext(ApplicationContext ctx) throws BeansException { logger.info("\r\n\r\n\r\n\r\n1 => StartupListener.setApplicationContext"); } @Override public void setServletContext(ServletContext context) { logger.info("\r\n\r\n\r\n\r\n2 => StartupListener.setServletContext"); } @Override public void afterPropertiesSet() throws Exception { logger.info("\r\n\r\n\r\n\r\n3 => StartupListener.afterPropertiesSet"); } @Override public void onApplicationEvent(ContextRefreshedEvent event) { logger.info("\r\n\r\n\r\n\r\n4.1 => MyApplicationListener.onApplicationEvent"); logger.info("\r\n\r\n\r\n\r\n4.1 => " + event.getApplicationContext().getParent()); logger.info("\r\n\r\n\r\n\r\n4.1 => " + event.getApplicationContext().getDisplayName()); if (event.getApplicationContext().getParent() == null) { logger.info("\r\n\r\n\r\n\r\n4.2 => MyApplicationListener.onApplicationEvent"); } else{ logger.info("\r\n\r\n\r\n\r\n4.4 => " + event.getApplicationContext().getParent().getDisplayName()); } if (event.getApplicationContext().getDisplayName().equals("Root We<i style="color:transparent">来源gaodai$ma#com搞$代*码网</i>bApplicationContext")){ logger.info("\r\n\r\n\r\n\r\n4.3 => MyApplicationListener.onApplicationEvent"); } } }

 Spring 2.5引入了更多典型化注解(stereotype annotations)： @Component、@Service和 @Controller。@Component是所有受Spring管理组件的通用形式；而@Repository、@Service和 @Controller则是@Component的细化，用来表示更具体的用例(例如，分别对应了持久化层、服务层和表现层)。也就是说，你能用@Component来注解你的组件类，但如果用@Repository、@Service 或@Controller来注解它们，你的类也许能更好地被工具处理，或与切面进行关联。例如，这些典型化注解可以成为理想的切入点目标。当然，在Spring Framework以后的版本中， @Repository、@Service和 @Controller也许还能携带更多语义。如此一来，如果你正在考虑服务层中是该用@Component还是@Service，那@Service显然是更好的选择。同样的，就像前面说的那样， @Repository已经能在持久化层中进行异常转换时被作为标记使用了。”