@RestController annotation in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @RestController annotation in Spring Boot?

The <code>@RestController</code> annotation marks a class as a controller where every method returns a domain object instead of a view. It combines <code>@Controller</code> and <code>@ResponseBody</code>, making it easier to create RESTful web services.

beginner

How does @RestController differ from @Controller in Spring Boot?

@RestController automatically serializes return objects to JSON or XML and sends them as HTTP responses. @Controller is used for web pages and requires explicit @ResponseBody to return data directly.

beginner

Can you use @RestController on multiple classes in a Spring Boot application?

Yes, you can use <code>@RestController</code> on multiple classes. Each class can handle different REST endpoints, helping organize your API logically.

intermediate

What HTTP response content type does @RestController typically produce?

@RestController typically produces JSON by default, but it can also produce XML or other formats if configured with message converters.

beginner

Why is @RestController considered a convenience annotation?

Because it combines @Controller and @ResponseBody, reducing boilerplate code and making REST API development simpler and cleaner.

What does the @RestController annotation do in Spring Boot?

A Marks a class as a view resolver for HTML pages

B Marks a class as a REST API controller that returns data directly

C Defines a database entity

D Configures security settings

@RestController is used to create REST APIs by returning data directly as JSON or XML.

Which two annotations does @RestController combine?

A <code>@Controller</code> and <code>@ResponseBody</code>

B <code>@Service</code> and <code>@Repository</code>

C <code>@Component</code> and <code>@Entity</code>

D <code>@RequestMapping</code> and <code>@PathVariable</code>

@RestController is a shortcut for @Controller plus @ResponseBody.

What is the default format of data returned by methods in a @RestController?

A HTML

B CSV

C Plain text

D JSON

By default, Spring Boot converts returned objects to JSON in @RestController methods.

If you want to return a web page instead of data, which annotation should you use instead of @RestController?

A <code>@Controller</code>

B <code>@Service</code>

C <code>@Repository</code>

D <code>@Component</code>

@Controller is used for returning views like HTML pages.

Can a Spring Boot application have multiple classes annotated with @RestController?

A Only if they extend a common base class

B No, only one is allowed

C Yes, to organize different API endpoints

D Only if they are in different packages

Multiple @RestController classes help organize APIs logically.

Explain what the @RestController annotation does and why it is useful in Spring Boot applications.

Think about how it simplifies returning data from web endpoints.

Describe the difference between @RestController and @Controller in Spring Boot.

Focus on what each annotation returns to the client.