Spring事件传播

ApplicationContext基于Observer模式（java.util包中有对应实现），提供了针对Bean的事件传播功能。通过Application. publishEvent方法，我们可以将事件通知系统内所有的ApplicationListener。

示例代码：

public class LoginAction implements ApplicationContextAware {
        private ApplicationContext applicationContext;

        public void setApplicationContext(
                 ApplicationContext applicationContext
                 )throws BeansException {
                this.applicationContext = applicationContext;
        }

        public int login(String username,String password) {
               ActionEvent event = new ActionEvent(username);
               this.applicationContext.publishEvent(event);
               return 0;
        }
}

ActionEvent.java:
public class ActionEvent extends ApplicationEvent {
      public ActionEvent(Object source) {
              super(source);
      }
}

ActionListener.java:
public class ActionListener implements ApplicationListener {
     public void onApplicationEvent(ApplicationEvent event) {
            if (event instanceof ActionEvent) {
               System.out.println(event.toString());
            }
     }
}

 

配置非常简单：

<bean id="loginaction" class="net.xiaxin.beans.LoginAction"/>
<bean id="listener" class="net.xiaxin.beans.ActionListener"/>

 

运行测试代码：

ApplicationContext ctx=new
FileSystemXmlApplicationContext("bean.xml");
LoginAction action = (LoginAction)ctx.getBean("action");
action.login("Erica","mypass");