JUnit not Initializing Services Parameters-CodePudding

I have a SpringBoot application, basically with a structure similar to the following:

application:

@SpringBootApplication
public class MyApplication {

@Autowired
MainService mainService;

    public static void main(String[] args) {

            SpringApplication.run(MyApplication.class, args);
    }


    @KafkaListener(topics = "myTopic")
    public void listen(String message) {

        this.graphicService.performWork();

     }
}

first service:

@Service
public MainService {

@Autowired MyService myService;

    public performWork() {

       this.myService.doStuff();
    }
}

second service:

@Service
public class MyService {

// server.param1 and server.param2 are defined in application.properties file
@Value("${server.param1}")
private String param1;
@Value("${server.param2}")
private String param2;

@PostConstruct
public void initService(){
}
    public void doStuff() {
        // do stuff assuming the parameters param1 and param 2 of this autowired service have already been initialized
   }
}

I have a junit like the following:

@SpringBootTest(classes = MyApplication.class)
class MyServiceTest {

    @Test
    void testMyService() {

        MyService myService = new MyService();

        myService.doStuff();
    }
}

When I execute testMyService, I get an exception thrown, essentially like this:

java.lang.IllegalStateException: Failed to load ApplicationContext
.
.
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myApplication': Unsatisfied dependency expressed through field 'mainService';
.
.
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'mainService': Unsatisfied dependency expressed through field 'myService'
.
.
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myService': Injection of autowired dependencies failed
.
.
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'server.param1' in value "${server.param1}"

The application works fine operationally. I thought that the way I set up the junit, the springboot app would simply fire up and the parameters found in the application.properties file would simply be available to MyService service as are they when I run the application itself (not the junit).

Obviously I am doing something wrong, and the application context is not available the way I have this junit set up. I would be grateful for any ideas for getting this to work properly.

Thanks!

CodePudding user response：

Wire your class under test in the Junit test like in any production code class.

The @SpringBootTest will autodetect the @SpringBootApplication, so no extra parameter is needed. Just wire the needed dependencies like you would in the application classes.

The test will use the src/test/resources/application.properties (or yml) file, if present. If not present, the src/main/resources/application.properties is used. So if you use environment variables in your production application.yml copy this file to the test resources and fill the parameters with dummy parameters for test.

@SpringBootTest
class MyServiceTest {

    @Autowired MyService myService;

    @Test
    void testMyService() {

        myService.doStuff();
    }
}

If you like you can add the parameters in the test class with @TestPropertySource(properties

@SpringBootTest
@TestPropertySource(properties = {
    "server.param1=srv1",
    "server.param2=srv2"
})
class MyServiceTest {
...

Make sure you have spring-boot-starter-test in your dependencies.

Maven Example:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <version>2.7.5</version>
    <scope>test</scope>
</dependency>