Spring Boot Building RESTful Services 2

Question 1

Which annotation is used to map HTTP PATCH requests to handler methods in Spring MVC?

Accepted Answer

@PatchMapping

Answer

@PatchMapping is the dedicated Spring MVC annotation for handling HTTP PATCH requests, used for partial resource updates.

Question 2

When a Spring REST controller method returns a ResponseEntity<Void> with HttpStatus.NO_CONTENT, what HTTP status code is sent to the client?

Accepted Answer

204

Answer

HttpStatus.NO_CONTENT maps to HTTP 204, indicating the request succeeded but the response body is intentionally empty.

Question 3

What does the @RequestParam(required = false) annotation do in a Spring REST controller?

Accepted Answer

Makes the query parameter optional with a null default

Answer

Setting required = false makes the query parameter optional; Spring injects null (or a specified defaultValue) when it is absent.

Question 4

Which Spring annotation allows you to handle exceptions globally across all @RestController classes?

Accepted Answer

@RestControllerAdvice

Answer

@RestControllerAdvice combines @ControllerAdvice and @ResponseBody to provide centralized exception handling with automatic JSON serialization.

Question 5

In Spring Boot, what is the default behavior when Jackson encounters an unknown JSON field during deserialization?

Accepted Answer

Ignores the unknown field

Answer

By default, Spring Boot configures Jackson with DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES set to false, so unknown fields are silently ignored.

Spring Boot Practice Test

Spring Boot Practice Test

Spring Boot Building RESTful Services 2