@Service annotation in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark the class as a service in Spring Boot.

Spring Boot

[1]
public class UserService {
    // service methods
}

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

A@Repository

B@Service

C@Controller

D@ComponentScan

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Controller instead of @Service

Forgetting to add any annotation

The @Service annotation marks the class as a service component in Spring Boot.

2fill in blank

medium

Complete the code to inject the service into a controller using Spring Boot.

Spring Boot

public class UserController {
    private final UserService userService;

    public UserController([1] userService) {
        this.userService = userService;
    }
}

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

AUserService

BInject

CService

D@Autowired

Attempts:

3 left

💡 Hint

Common Mistakes

Using annotation names as parameter type

Forgetting to use the service class type

The constructor parameter must be the type UserService to inject the service.

3fill in blank

hard

Fix the error in the service class declaration by adding the missing annotation.

Spring Boot

[1]
public class OrderService {
    public void processOrder() {
        // processing logic
    }
}

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

A@Repository

B@Component

C@Controller

D@Service

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Component instead of @Service

Not adding any annotation

The @Service annotation is required to register the class as a service bean.

4fill in blank

hard

Fill both blanks to create a service class and inject it into a controller.

Spring Boot

@Service
public class ProductService {
    public String getProduct() {
        return "Product";
    }
}

public class ProductController {
    private final [1] productService;

    public ProductController([2] productService) {
        this.productService = productService;
    }
}

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

AProductService

BUserService

COrderService

DProductController

Attempts:

3 left

💡 Hint

Common Mistakes

Using controller class name instead of service

Mixing different service class names

Both blanks require the service class name ProductService to correctly declare and inject the service.

5fill in blank

hard

Fill all three blanks to define a service, annotate it, and inject it into a controller.

Spring Boot

[1]
public class CustomerService {
    public String getCustomer() {
        return "Customer";
    }
}

public class CustomerController {
    private final [2] customerService;

    public CustomerController([3] customerService) {
        this.customerService = customerService;
    }
}

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

A@Service

BCustomerService

D@Controller

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Controller instead of @Service

Mismatching types in field and constructor

The service class must be annotated with @Service. The field and constructor parameter types must be CustomerService.