Request validation preview in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of request validation in Spring Boot?

Request validation ensures that the data sent by a client meets the expected rules before processing. It helps prevent errors and security issues by checking inputs early.

beginner

Which annotation is commonly used to trigger validation on a request object in Spring Boot?

The @Valid annotation is used on a method parameter to tell Spring Boot to validate the object according to its constraints.

beginner

How do you define validation rules on a request data class in Spring Boot?

You add annotations like @NotNull, @Size, @Email, etc., on the fields of the class to specify rules that must be met.

intermediate

What happens if a request fails validation in Spring Boot?

Spring Boot automatically returns a 400 Bad Request response with details about which fields failed validation.

intermediate

How can you customize the error messages returned when validation fails in Spring Boot?

You can provide custom messages in the validation annotations or use a messages.properties file to define friendly error texts.

Which annotation triggers validation on a request body in Spring Boot?

A @RequestMapping

B @Autowired

C @Component

D @Valid

The @Valid annotation tells Spring Boot to validate the request object based on its constraints.

What HTTP status code does Spring Boot return when validation fails by default?

A 404 Not Found

B 200 OK

C 400 Bad Request

D 500 Internal Server Error

Spring Boot returns 400 Bad Request when the input data does not meet validation rules.

Which annotation would you use to ensure a string field is not empty in a request object?

A @NotEmpty

B @NotNull

C @Email

D @Pattern

@NotEmpty ensures the string is not null and not empty, preventing empty strings.

Where do you place validation annotations in Spring Boot request validation?

A On controller methods

B On fields of the request data class

C On service classes

D On the main application class

Validation annotations go on the fields of the class representing the request data.

How can you customize validation error messages in Spring Boot?

A By adding messages in messages.properties or in annotation attributes

B By disabling validation

C By changing the HTTP status code

D By editing the controller code

Custom messages can be set in annotation attributes or externalized in messages.properties files.

Explain how request validation works in Spring Boot and how you set it up.

Think about annotations and automatic error handling.

Describe ways to customize validation error messages in Spring Boot.

Focus on how to make error messages clearer for users.