Bean concept in Spring in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a Spring bean using annotation.

Spring Boot

@Configuration
public class AppConfig {
    @Bean
    public MyService [1]() {
        return new MyService();
    }
}

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

AcreateService

BserviceBean

CmyService

DgetService

Attempts:

3 left

💡 Hint

Common Mistakes

Using method names that do not follow Java naming conventions.

Forgetting to annotate the method with @Bean.

The method name myService is used as the bean name by default in Spring when using @Bean.

2fill in blank

medium

Complete the code to inject a bean into a Spring component using annotation.

Spring Boot

@Component
public class UserController {
    private final UserService userService;

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

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

A@Autowired

B@Inject

C@Qualifier

D@Resource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Qualifier without specifying a bean name.

Forgetting to annotate the constructor parameter.

The @Autowired annotation tells Spring to inject the bean automatically into the constructor.

3fill in blank

hard

Fix the error in the bean scope declaration.

Spring Boot

@Bean
@Scope([1])
public SessionBean sessionBean() {
    return new SessionBean();
}

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

A"prototype"

B"session"

C"singleton"

D"request"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "singleton" scope for session-specific beans.

Forgetting to import the correct Scope annotation.

The "session" scope defines a bean that is created once per HTTP session in Spring web applications.

4fill in blank

hard

Fill both blanks to create a bean with a custom name and prototype scope.

Spring Boot

@Bean(name = "[1]")
@Scope("[2]")
public ProductService [3]() {
    return new ProductService();
}

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

AcustomProductService

Bsingleton

Cprototype

DproductService

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the bean name and method name.

Using singleton scope instead of prototype.

The bean is named customProductService, has prototype scope, and the method name is productService.

5fill in blank

hard

Fill all three blanks to define a bean with lazy initialization, singleton scope, and a qualifier.

Spring Boot

@Bean
@Lazy([1])
@Scope("[2]")
@Qualifier("[3]")
public NotificationService notificationService() {
    return new NotificationService();
}

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

Atrue

Bfalse

Csingleton

DemailService

Attempts:

3 left

💡 Hint

Common Mistakes

Setting lazy to false when lazy initialization is desired.

Using incorrect qualifier names.

The bean is lazily initialized (true), has singleton scope, and is qualified with emailService.