Why IoC matters in Spring Boot - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a Spring component using IoC.

Spring Boot

@[1]
public class MyService {
    // service logic
}

Drag options to blanks, or click blank then click option'

AService

BComponent

CAutowired

DRepository

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Autowired instead of a component annotation

Using @Repository for a service class

The @Service annotation marks the class as a Spring service component managed by IoC.

2fill in blank

medium

Complete the code to inject a dependency using IoC in Spring.

Spring Boot

public class MyController {
    @[1]
    private MyService myService;
}

Drag options to blanks, or click blank then click option'

AComponent

BAutowired

CService

DInject

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Component instead of @Autowired

Using @Service on fields

The @Autowired annotation tells Spring to inject the dependency automatically.

3fill in blank

hard

Fix the error in the code to properly use IoC for dependency injection.

Spring Boot

public class MyController {
    private MyService myService;

    public MyController([1] MyService myService) {
        this.myService = myService;
    }
}

Drag options to blanks, or click blank then click option'

A@Autowired

BAutowired

C@Inject

DInject

Attempts:

3 left

💡 Hint

Common Mistakes

Missing @ symbol

Using plain 'Autowired' without @

Using @Inject without proper setup

The constructor parameter needs the @Autowired annotation for Spring to inject the dependency via constructor.

4fill in blank

hard

Fill both blanks to create a Spring bean and inject it using IoC.

Spring Boot

@[1]
public class NotificationService {
}

public class UserController {
    @[2]
    private NotificationService notificationService;
}

Drag options to blanks, or click blank then click option'

AComponent

BAutowired

CService

DInject

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Service instead of @Component here

Forgetting @Autowired on the field

@Component marks the class as a Spring bean, and @Autowired injects it where needed.

5fill in blank

hard

Fill all three blanks to define a Spring service, inject it, and use it in a method.

Spring Boot

@[1]
public class EmailService {
    public void sendEmail() {
        System.out.println("Email sent");
    }
}

public class NotificationController {
    @[2]
    private EmailService emailService;

    public void notifyUser() {
        emailService.[3]();
    }
}

Drag options to blanks, or click blank then click option'

AService

BAutowired

CsendEmail

DComponent

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Component instead of @Service for service class

Forgetting to call the method

Missing @Autowired annotation

@Service marks the class as a service bean, @Autowired injects it, and sendEmail() calls the method.