精通SpringBoot——第四篇：Spring事件 Application Event

Spring的事件为Bean与Bean之间的通信提供了支持，当我们系统中某个Spring管理的Bean处理完某件事后，希望让其他Bean收到通知并作出相应的处理，这时可以让其他Bean监听当前这个Bean所发送的事件。

要实现事件的监听，我们要做两件事：
1：自定义事件，继承ApplicationEvent接口
2：定义事件监听器，实现ApplicationListener
3：事件发布类

 /** * @TODO // 自定义事件，继承ApplicationEvent接口 * @Author Lensen * @Date 2018/7/22 * @Description */ public class SendMsgEvent extends ApplicationEvent { private static final long serialVersionID = 1L; // 收件人 public String receiver; // 收件内容 public String content; public SendMsgEvent(Object source) { super(source); } public SendMsgEvent(Object source, String receiver, String content) { super(source); this.receiver = receiver; this.content = content; } public void output(){ System.out.println("I had been sand a msg to " + this.receiver); } } 

 /** * @TODO //定义事件监听器，实现ApplicationListener * @Author Lensen * @Date 2018/7/22 * @Description */@Component public class MsgListener implements ApplicationListener<SendMsgEvent> { @Override public void onApplicationEvent(SendMsgEvent sendMsgEvent) { sendMsgEvent.output(); System.out.println(sendMsgEvent.receiver + "received msg : " + sendMsgEvent.content ); } }

事件发布类

@Component public class Publisher { @Autowired ApplicationContext applicationContext; public void publish(Object source, String receiver, String content){ applicationContext.publishEvent(new SendMsgEvent(source, receiver, content)); } }

测试消息：WebConfig.class主要是为了扫描Publisher 和Listener类。里面有两个注解@ComponenScan和@Configuration。

 public static void main(String[] args) { AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(WebConfig.class); Publisher publisher = applicationContext.getBean(Publisher.class); publisher.publish("Hello,World!","Mr.Lensen", "I Love U"); }

结果：

I had been sand a msg to Mr.Lensen Mr.Lensen received msg : I Love U