Close

Spring Framework - ApplicationEventPublisher Examples

Spring Framework 

Autowiring ApplicationEventPublisher for firing spring custom event. 

    private static class MyEvenPublisherBean{
        @Autowired
        ApplicationEventPublisher publisher;

        public void sendMsg(String msg){
            publisher.publishEvent(new MyEvent(this, msg));
        }

    }
Original Post




Firing event with ApplicationEventPublisher.

This example shows how to autowire ApplicationEventPublisher for firing the custom event. Also to create custom event, we don't need to extend ApplicationEvent anymore (since Spring 4.2), we just need a POJO.

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.event.EventListener;

public class CustomEventWithoutApplicationEvent {

    @Bean
    AListenerBean listenerBean () {
        return new AListenerBean();
    }

    @Bean
    MyEvenPublisherBean publisherBean () {
        return new MyEvenPublisherBean();
    }


    public static void main (String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
                            CustomEventWithoutApplicationEvent.class);
        MyEvenPublisherBean bean = context.getBean(MyEvenPublisherBean.class);
        bean.sendMsg("A test message");
    }

    private static class MyEvenPublisherBean{
        @Autowired
        ApplicationEventPublisher publisher;

        public void sendMsg(String msg){
            publisher.publishEvent(new MyEvent(msg));
        }
    }

    private static class AListenerBean {

        @EventListener
        public void onMyEvent (MyEvent event) {
            System.out.print("event received: "+event.getMsg());
        }
    }

    /**
     * This time we are not extending any ApplicationEvent
     */
    private static class MyEvent{
        private final String msg;

        public MyEvent (String msg) {
            this.msg = msg;
        }

        public String getMsg () {
            return msg;
        }
    }
}
Original Post




ApplicationEventPublisher is an ApplicationContext

Since ApplicationEventPublisher is a super interface of ApplicationContext, the events can directly be fired with 'context' instance.

        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext(EventListenerConditionExample.class);
        context.publishEvent(new MyEvent(1, "test message 1"));
        context.publishEvent(new MyEvent(5, "test message 5"));
Original Post

See Also