Spring Boot properties in 'application.yml'

Question

What am I doing wrong? I'm using this little standalone App which runs and finds my src/main/resources/config/application.yml. The same configuration doesn't work from JUnit, see below:

@Configuration
@ComponentScan
@EnableConfigurationProperties

public class TestApplication {

    public static void main(String[] args) {

        SpringApplication.run(TestApplication.class);
    }
}


@Component
@ConfigurationProperties

public class Bean{
    ...
}

The following doesn't work, the same properties in application.yml are not loaded and Bean has only null values:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = TestApplication.class)

public class SomeTestClass {
    ...
}

Answer 1

Unit test with Spring Boot 2

spring boot 2 support 'application.properties' by default, for 'application.yml' just add below:

@TestPropertySource(properties = { "spring.config.location=classpath:application.yml" })

e.g.

@RunWith(SpringRunner.class)
@SpringBootTest
@TestPropertySource(properties = { "spring.config.location=classpath:application.yml" })
public class ServiceTest {...}

Answer 2

The trick to load any custom yml file in SpringBoot 2.0 w/o using @SpringBootTest

• create some yml file in test\resources
• Use ConfigFileApplicationContextInitializer and spring.config.location property

Example Code:

@RunWith(SpringRunner.class)
@ContextConfiguration(
    classes = { MyConfiguration.class, AnotherDependancy.class },
    initializers = {ConfigFileApplicationContextInitializer.class} )
@TestPropertySource(properties = { "spring.config.location=classpath:myApp-test.yml" })
public class ConfigProviderTest {
    @Autowired
    private MyConfiguration myConfiguration; //this will be filled with myApp-test.yml 

   @Value("${my.config-yml-string}")
   private String someSrting; //will get value from the yml file.

}

For JUnit 5 use the @ExtendWith(SpringExtension.class) annotation instead of @RunWith(SpringRunner.class)

Answer 3

This works

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class ApplicationTest {

    @Test
    public void contextLoads() {
    }

}

Answer 4

Alternative in February 2017:

@SpringBootTest
@ContextConfiguration(classes = { TestApplication.class })
@RunWith(SpringRunner.class)
public class SomeTestClass {
   ...
}

the lean variant (withouth @SpringBootTest):

@ContextConfiguration(classes = { TestApplication.class },
                 initializers = { ConfigFileApplicationContextInitializer.class })
@RunWith(SpringRunner.class)
public class SomeTestClass {

Answer 5

Here's another way: [Spring Boot v1.4.x]

@Configuration
@ConfigurationProperties(prefix = "own")
public class OwnSettings {

    private String name;
    Getter & setters...

}

---

import org.springframework.boot.test.context.SpringBootTestContextBootstrapper;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@BootstrapWith(SpringBootTestContextBootstrapper.class)
public class OwnSettingsTest {

  @Autowired
  private OwnSettings bean;

  @Test
  public void test() {
    bean.getName();
  }
}

This works ONLY if also 'application.properties' file exists.

e.g. maven project:

src/main/resources/application.properties [ The file can be empty but it's mandatory! ]
src/main/resources/application.yml [here's your real config file]

Answer 6

Try this:

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = TestApplication.class, 
    initializers = ConfigFileApplicationContextInitializer.class)
public class SomeTestClass {
    ...
}

EDIT:

For Spring Boot version 1.5+, SpringApplicationConfiguration was removed in favour of SpringBootTest or direct use of SpringBootContextLoader.

You can still use initializers parameter with ContextConfiguration annotation.