@Qualifier for ambiguous beans in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to inject a specific bean using @Qualifier.

Spring Boot

@Autowired
@Qualifier("paymentService")
private Service [1];

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

AService

Bservice

CpaymentService

Dbean

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name instead of the bean name.

Using a generic variable name that causes ambiguity.

You need to specify the exact bean name to resolve ambiguity using @Qualifier or bean name injection.

2fill in blank

medium

Complete the annotation to specify which bean to inject.

Spring Boot

@Autowired
@Qualifier("[1]")
private Service service;

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

ApaymentService

Bservice

CService

Dbean

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the quotes around the bean name.

Using the class name instead of the bean name.

The @Qualifier annotation requires the exact bean name as a string to resolve ambiguity.

3fill in blank

hard

Fix the error in the injection by adding the correct annotation.

Spring Boot

@Autowired
[1]
private Service service;

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

ApaymentService

Bbean

Cservice

D@Qualifier("paymentService")

Attempts:

3 left

💡 Hint

Common Mistakes

Only renaming the variable without @Qualifier.

Using @Qualifier without specifying the bean name.

To fix ambiguity, you must add @Qualifier with the bean name above the field or on the field declaration.

4fill in blank

hard

Fill both blanks to declare and inject the correct bean using @Qualifier.

Spring Boot

@Autowired
@Qualifier("[1]")
private [2] service;

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

ApaymentService

BOrderService

CUserService

Dservice

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing bean names and class types incorrectly.

Using a generic class type that does not match the bean.

You specify the bean name in @Qualifier and the correct service class type for the variable.

5fill in blank

hard

Fill all three blanks to define two beans and inject one using @Qualifier.

Spring Boot

@Bean
public [1] [2]() {
    return new [1]();
}

@Autowired
@Qualifier("[2]")
private [1] service;

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

APaymentService

BpaymentService

COrderService

DorderService

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for bean and qualifier.

Mismatching class type and bean name.

Define a bean method with the class and bean name, then inject it using @Qualifier with the bean name.