Spring Boot Building RESTful Services Questions and Answers

Question 1

A developer needs to create a REST endpoint that returns a `201 Created` status code upon successful creation of a resource, and a response body containing the newly created object.
Which approach is most appropriate for this scenario in a Spring Boot controller?

Accepted Answer

Return a `ResponseEntity` object, explicitly setting the status to `HttpStatus.CREATED` and including the object in the body.

Answer

Annotate the controller method with `@ResponseStatus(HttpStatus.CREATED)` and return the created object directly.

Answer

Return the created object directly and let Spring Boot default to a `200 OK` status, as the client can infer success.

Answer

Throw a custom `ResourceCreatedException` annotated with `@ResponseStatus(HttpStatus.CREATED)`.

Question 2

What is the primary purpose of including the `spring-boot-starter-hateoas` dependency in a Spring Boot project?

Accepted Answer

To add support for building hypermedia-driven RESTful services by easily creating links to related resources.

Answer

To enable automatic generation of OpenAPI (Swagger) documentation for the REST API.

Answer

To provide a centralized mechanism for handling exceptions across all controllers.

Answer

To configure content negotiation to support both JSON and XML response formats automatically.

Question 3

A REST service needs to support different versions of its API. A decision is made to include the version number in the URL path (e.g., `/api/v1/products` and `/api/v2/products`). Which of the following API versioning strategies does this describe?

Accepted Answer

URI Path Versioning

Answer

Query Parameter Versioning

Answer

Custom Header Versioning

Answer

Content Negotiation Versioning

Question 4

In a Spring Boot REST application, what is the role of the `@RestControllerAdvice` annotation?

Accepted Answer

To provide global, cross-controller exception handling and other request/response modifications.

Answer

To define a base controller from which all other `@RestController` classes must inherit.

Answer

To automatically convert controller method return values into JSON or XML based on the `Accept` header.

Answer

To enable Aspect-Oriented Programming (AOP) specifically for REST controllers.

Question 5

A client sends a GET request to a Spring Boot REST endpoint with an `Accept` header of `application/xml`. The corresponding controller method returns a POJO. For the application to correctly serialize the POJO into XML, which dependency is typically required on the classpath?

Accepted Answer

jackson-dataformat-xml

Answer

spring-boot-starter-thymeleaf

Answer

spring-boot-starter-security

Answer

spring-boot-starter-aop

Question 6

A developer creates a custom exception, `ResourceNotFoundException`, and wants any controller that throws it to automatically result in an HTTP `404 Not Found` response without using `@ExceptionHandler`. Which annotation should be placed on the `ResourceNotFoundException` class itself to achieve this?

Accepted Answer

@ResponseStatus(HttpStatus.NOT_FOUND)

Answer

@ControllerAdvice

Answer

@ResponseBody

Answer

@RequestMapping("/error")