Why input validation is critical in Spring Boot - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add input validation annotation for a non-empty string in Spring Boot.

Spring Boot

@NotBlank(message = "Name cannot be empty")
private String [1];

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

Ausername

Bprice

Cage

Dcount

Attempts:

3 left

💡 Hint

Common Mistakes

Using a numeric field like age or price with @NotBlank causes errors.

Leaving the field name blank or misspelled.

The @NotBlank annotation is used to ensure the string is not empty or null. Here, it is applied to the username field to validate user input.

2fill in blank

medium

Complete the code to validate that an integer input is at least 18 in Spring Boot.

Spring Boot

@Min(value = [1], message = "Age must be at least 18")
private int age;

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

A16

B0

C18

D21

Attempts:

3 left

💡 Hint

Common Mistakes

Using a value less than 18 allows invalid ages.

Using a value greater than 18 unnecessarily restricts input.

The @Min annotation ensures the integer value is not less than the specified minimum. Here, it validates that age is at least 18.

3fill in blank

hard

Fix the error in the code to correctly validate an email input in Spring Boot.

Spring Boot

@Email(message = "Invalid email format")
private String [1];

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

AphoneNumber

Busername

Cpassword

DemailAddress

Attempts:

3 left

💡 Hint

Common Mistakes

Applying email validation to phone number or password fields.

Using a field name unrelated to email.

The @Email annotation validates that the string is a valid email format. It should be applied to the emailAddress field.

4fill in blank

hard

Fill both blanks to create a validated DTO class with a non-null name and age at least 21.

Spring Boot

public class UserDTO {
    @[1](message = "Name is required")
    private String name;

    @[2](value = 21, message = "Must be at least 21")
    private int age;
}

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

ANotNull

BMin

CNotBlank

DMax

Attempts:

3 left

💡 Hint

Common Mistakes

Using @NotNull instead of @NotBlank for strings allows empty names.

Using @Max instead of @Min for age validation.

@NotBlank ensures the name is not null or empty. @Min(21) ensures age is at least 21.

5fill in blank

hard

Fill all three blanks to create a Spring Boot controller method that validates input and returns a response.

Spring Boot

@PostMapping("/register")
public ResponseEntity<String> registerUser(@Valid @RequestBody [1] user) {
    if (user.getAge() [2] 18) {
        return ResponseEntity.status(HttpStatus.[3]).body("User too young");
    }
    return ResponseEntity.ok("User registered");
}

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

AUserDTO

B<

CFORBIDDEN

DUserEntity

Attempts:

3 left

💡 Hint

Common Mistakes

Using entity class instead of DTO for input validation.

Using wrong comparison operator like '>' instead of '<'.

Returning wrong HTTP status code.

The method accepts a validated UserDTO object. It checks if age is less than 18. If so, it returns a 403 FORBIDDEN status with a message.