The Controller and RestController in the Spring framework are both used to handle the HTTP requests, but they have a difference in their intended use and their behaviour.
Difference between Controller and RestController
| Controller | RestController |
| The controller in Spring typically handles the traditional web requests and produces the HTML views. | RestContoller is specifically designed to handle the Restful web services. |
| Methods of the controller class return a string value representing a “view” that will be further resolved by view-resolver to populate the JSP pages. | The methods of the RestContoller return the RESTful data in the form of JSON or XML. |
| It is suitable for the application where the end user or the client expects to receive the HTML or JSP pages. | RestControllers are suitable for the application where the client expects RESTful data as a response. |
| Typically used in MVC (Model-View-Contoller) architecture. | It is commonly used in the RESTful applications where the views are not part of the backend system. |
| Example: e-commerce websites where the servers need to render the HTML pages to be displayed in browsers. | Example: Mobile banking apps where the clients need to interact with the servers to check account balances, fund transfers, etc. |
When to use Controller vs RestController
- Use of Controller
- Developing web application where the user expects to receive HTML views (server-side rendering)
- Applications using JSP, Thymeleaf or similar templates.
- Working on traditional MVC applications that rely on the page reloads.
Java
@Controller
public class ProductController {
@GetMapping("/product/{id}")
public String showProductPage(@PathVariable Long id, Model model) {
Product product = productService.findProductById(id);
model.addAttribute("product", product);
return "product-details"; // Refers to an HTML page "product-details.html"
}
}- Use of RestController
- While develoing RESTful web service or APIs where client consumes data in form of JSON or XML.
- When we need to expose our backend services to be used by front-end frameworks (Angular/React), mobile apps or other systems.
- Working with microservices or APIs that interacts with other services in a microservice architecture.
Java
@RestController
@RequestMapping("/api/accounts")
public class AccountController {
@GetMapping("/{id}")
public ResponseEntity<Account> getAccountById(@PathVariable Long id) {
Account account = accountService.findAccountById(id);
if (account != null) {
return new ResponseEntity<>(account, HttpStatus.OK);
} else {
return new ResponseEntity<>(HttpStatus.NOT_FOUND);
}
}
}