Spring事件监听基本原理与使用详解

public class MyEvent extends ApplicationEvent {
    private String msg;
    // 必须继承实现
    public MyEvent(Object source, String msg) {
        super(source);
        this.msg = msg;
    }
    @Override
    public String toString() {
        return "MyEvent{" +
                "msg='" + msg + '\'' +
                '}';
    }
}

// 装载入spring容器中
@Slf4j
@Component
public class MyListener1 implements ApplicationListener<MyEvent> {
    @Override
    public void onApplicationEvent(MyEvent event) {
        // 这里可以自定义自己的方法
        log.info(String.format("%s监听到事件源：%s.", MyListener1.class.getName(), event.toString()));
    }
}

@SpringBootApplication
public class ListenerApplication {
    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(ListenerApplication.class, args);
        //装载监听
        context.addApplicationListener(new MyListener1());
    }
}

@Component
@Slf4j
public class MyListener2{
    // 通过注解的方法
    @EventListener(MyEvent.class)
    public void consumer(MyEvent msgEvent) {
        log.info(String.format("%s监听到事件源：%s.", MsgPublisher.class.getName(), msgEvent.toString()));
    }
}

@Component
@Slf4j
public class MsgPublisher implements ApplicationContextAware {
    private ApplicationContext applicationContext;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
    // 发起事件通知
    public void publish(String msg) {
        applicationContext.publishEvent(new MyEvent1(this, msg));
    }
    // 通过注解的方法
    @EventListener(MyEvent.class)
    public void consumer(MyEvent msgEvent) {
        log.info(String.format("%s监听到事件源：%s.", MsgPublisher.class.getName(), msgEvent.toString()));
    }
    /**
     * 这个只是测试，到时候spring直接调用即可
    */
    public static void main(String[] args) {
        ApplicationContext context = new AnnotationConfigApplicationContext(MsgPublisher.class);
        MsgPublisher msgPublisher = context.getBean(MsgPublisher.class);
        msgPublisher.publish("hello world");
    }
}