spring发布和接收事件

EventObject，为JavaSE提供的事件类型基类，任何自定义的事件都继承自该类，例如上图中右侧灰色的各个事件。Spring中提供了该接口的子类ApplicationEvent。

EventListener为JavaSE提供的事件监听者接口，任何自定义的事件监听者都实现了该接口，如上图左侧的各个事件监听者。Spring中提供了该接口的子类ApplicationListener接口。

JavaSE中未提供事件发布者这一角色类，由各个应用程序自行实现事件发布者这一角色。Spring中提供了ApplicationEventPublisherAware接口作为事件发布者。

1、编写事件

public class MyEvent extends ApplicationEvent {

    /**
     *
     */
    private static final long serialVersionUID = -1002815320277254124L;

    private String methodName;

    public MyEvent(Object source) {
        super(source);
    }

    public MyEvent(Object source, String methodName){
        super(source);
        this.methodName = methodName;
    }

    public String getMethodName() {
        return methodName;
    }

    public void setMethodName(String methodName) {
        this.methodName = methodName;
    }

}

2、编写事件监听者

public class MyEventListener implements ApplicationListener<ApplicationEvent> {

    @Override
    public void onApplicationEvent(ApplicationEvent event) {
        if (event instanceof MyEvent) {
            MyEvent event2=(MyEvent) event;
            System.out.println("执行自定义事件!"+event2.getMethodName());
        }
    }

}

3、编写事件发布者

public class MyPublisher implements ApplicationEventPublisherAware {

    private ApplicationEventPublisher applicationEventPublisher;

    @Override
    public void setApplicationEventPublisher(
            ApplicationEventPublisher applicationEventPublisher) {
        this.applicationEventPublisher=applicationEventPublisher;
    }

    public void methodToMonitor() {
        applicationEventPublisher.publishEvent(new MyEvent(this, "aaa"));
        applicationEventPublisher.publishEvent(new MyEvent(this, "bbb"));
    }  

}

4、测试

public static void main(String[] args) {
    ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
    MyPublisher myPublisher=applicationContext.getBean("myPublisher",MyPublisher.class);
    myPublisher.methodToMonitor();
}

输出

执行自定义事件!aaa
执行自定义事件!bbb