如何在Spring Boot应用程序中模拟外部依赖关系？

Question

I have a requirement to test a SpringBoot application where I run the tests against the end point (for now, locally).

There is one call from a service to external service ( s3 ), and I just need to mock this, so that we don't do a live call to s3 from our test.

I use Mockito for mocking.

The call stack:

Controller -service

                   -external service.

From my test, I just hit the end point url ( localhost:8080/actions/domyjob )

This is my controller:

@RestController
@RequestMapping("/myjob")
public class MyController{

    @Autowired
    private MyService myService;

    @RequestMapping(path = "/doJobInMyService", method = POST)
    public void doJobInMyService(){
        myService.doMyJob()
    }

}

This is my service:

@Service
public class MyService {

    @Autowired
    private s3Client AmazonS3Client;

     doMyJob() {
    s3Client.putObject(new PutObjectRequest());
}
}

If you see, if I want to test the entire flow, by calling localhost:8080/myjob/doJobInMyService and just mock s3Client.putObject(new PutObjectRequest()) , so that external calls to s3 is not done.

Tried this, but I had still no luck:

@ActiveProfiles("MyTestConfig")
@RunWith(SpringJUnit4ClassRunner.class)
public class MyTest extends BaseTest {
    @Autowired
    private AmazonS3Client amazonS3Client;

    @Test
    public void testMyResponse() {
        try {
            Mockito.when(amazonS3Client.putObject(anyObject())).thenReturn(new PutObjectResult());
            assertNotNull(getMyClient().doMyJob());
        } catch(Exception e) {

        }
    }
}

@Profile("MyTestConfig")
@Configuration
public class MyTestConfiguration {

    @Bean
    @Primary
    public AmazonS3Client amazonS3Client() {
        return Mockito.mock(AmazonS3Client.class);
    }

Answer 1

Since Spring Boot 1.4.x, there is Mockito mocking of Spring beans natively supported via annotation @MockBean . See this section of Spring Boot docs for more info.

Answer 2

I created blog post on the topic . It contains also link to Github repository with working example.

The trick is using test configuration, where you override original spring bean (eg s3Client in your case) with fake one. You can use @Primary and @Profile annotations for this trick.