Override a single @Configuration class on every spring boot @Test

Inner test configuration

Example of an inner @Configuration for your test:

@RunWith(SpringRunner.class)@SpringBootTestpublic class SomeTest {    @Configuration    static class ContextConfiguration {        @Bean        @Primary //may omit this if this is the only SomeBean defined/visible        public SomeBean someBean () {            return new SomeBean();        }    }    @Autowired    private SomeBean someBean;    @Test    public void testMethod() {        // test    }}

Reusable test configuration

If you wish to reuse the Test Configuration for multiple tests, you may define a standalone Configuration class with a Spring Profile @Profile("test"). Then, have your test class activate the profile with @ActiveProfiles("test"). See complete code:

@RunWith(SpringRunner.class)@SpringBootTests@ActiveProfiles("test")public class SomeTest {    @Autowired    private SomeBean someBean;    @Test    public void testMethod() {        // test    }}@Configuration@Profile("test")public class TestConfiguration {    @Bean    @Primary //may omit this if this is the only SomeBean defined/visible    public SomeBean someBean() {        return new SomeBean();    }}

@Primary

The @Primary annotation on the bean definition is to ensure that this one will have priority if more than one are found.

You should use spring boot profiles:

1. Annotate your test configuration with @Profile("test").
2. Annotate your production configuration with @Profile("production").
3. Set production profile in your properties file: spring.profiles.active=production.
4. Set test profile in your test class with @Profile("test").

So when your application starts it will use "production" class and when test stars it will use "test" class.

If you use inner/nested @Configuration class it will be be used instead of a your application’s primary configuration.

I recently had to create a dev version of our application, that should run with dev active profile out of the box without any command line args. I solved it with adding this one class as a new entry, which sets the active profile programmatically:

package ...;import org.springframework.boot.SpringApplication;import org.springframework.context.annotation.Import;import org.springframework.core.env.ConfigurableEnvironment;import org.springframework.core.env.StandardEnvironment;@Import(OriginalApplication.class)public class DevelopmentApplication {    public static void main(String[] args) {        SpringApplication application =            new SpringApplication(DevelopmentApplication.class);        ConfigurableEnvironment environment = new StandardEnvironment();        environment.setActiveProfiles("dev");        application.setEnvironment(environment);        application.run(args);    }}

See Spring Boot Profiles Example by Arvind Rai for more details.