How to Capture ApplicatonEvent in Spring boot integration test?

Question

The issue is that Application Event is not being captured in Spring boot test While it works fine for files listening to event in app project.

I want to capture an ApplicationEvent in Spring boot test(don't want to do Unit testing). My goal is to capture this application event and then perform few tasks in my test to verify the end-to-end functionality. Since, the event is not being captured in test case so I am not able to write integration tests.

Please let me know what is wrong with the code.

Thanks All.

package com.example.demo;

import org.springframework.context.ApplicationEvent;

public class CacheRefreshEvent extends ApplicationEvent {
    private String message;

    private static final long serialVersionUID = 1L;

    public CacheRefreshEvent(Object source, String message) {
        super(source);
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

package com.example.demo;

import org.springframework.context.ApplicationEvent;

public class CacheRefreshCompleteEvent extends ApplicationEvent {
    private String message;

    private static final long serialVersionUID = 1L;

    public CacheRefreshCompleteEvent(Object source, String message) {
        super(source);
        this.message = message;
    }

    public String getMessage() {
        return message;
    }
}

package com.example.demo;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.ApplicationListener;
import org.springframework.stereotype.Component;

@Component
public class CaptureCacheRefreshCompleteEvent implements ApplicationListener {

    private ApplicationEventPublisher applicationEventPublisher;

    void applicationEvent() throws InterruptedException {
        applicationEventPublisher.publishEvent(new CacheRefreshEvent(this, "event triggered from SolrUtilitiesTest()"));
        Thread.sleep(5000);
        System.out.println("Finished execution of test.");
    }

    public void onApplicationEvent(CacheRefreshCompleteEvent cs) {
        System.out.println("gotcha in CaptureCachedRefreshCompleteEvent");
    }

    public void setApplicationEventPublisher(ApplicationEventPublisher arg0) {
        this.applicationEventPublisher = arg0;
    }

}

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

package com.example.demo;

import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationEventPublisherAware;
import org.springframework.context.ApplicationListener;
import org.springframework.test.annotation.DirtiesContext;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@DirtiesContext
@SpringBootTest
class DemoApplicationTests implements ApplicationEventPublisherAware, ApplicationListener {

    @Autowired
    private ApplicationEventPublisher applicationEventPublisher;

    @Test
    void applicationEvent() throws InterruptedException {
        applicationEventPublisher.publishEvent(new CacheRefreshEvent(this, "event triggered from Springboot test"));
        for(int i=0; i< 20; i ++) {
            Thread.sleep(1000);
        }
        System.out.println("Finished execution of test.");
    }

    public void onApplicationEvent(CacheRefreshCompleteEvent cs) {
        System.out.println("gotcha");
    }

    @Override
    public void setApplicationEventPublisher(ApplicationEventPublisher arg0) {
        this.applicationEventPublisher = arg0;
    }

}

user_711906 · Answer

One way could be to create a very simple listener with @TestComponent inside your test and autowire it as a @MockBean.

Proof of concept (tested with Spring Boot 2.2 and 2.1):

@SpringBootTest
public class PublishTest {
    @Autowired
    private ApplicationEventPublisher applicationEventPublisher;

    @MockBean
    private Consumer consumer;

    @Test
    public void test() {
        applicationEventPublisher.publishEvent(new TestEvent(this));

        // events are synchronous by default

        verify(consumer).consumeEvent(any(TestEvent.class));
    }

    @TestComponent
    private static class Consumer {
        @EventListener
        public void consumeEvent(TestEvent testEvent) {
        }
    }

    private static class TestEvent extends ApplicationEvent {
        public TestEvent(Object source) {
            super(source);
        }
    }
}

How to Capture ApplicatonEvent in Spring boot integration test?

1 Answers