What is @RestController and how is it different from @Controller? @RestController क्या है और यह @Controller से कैसे अलग है?

@RestController is a convenience annotation that combines @Controller and @ResponseBody. It marks a class as a request handler where every method's return value is written directly to the HTTP response body, serialized as JSON or XML, instead of being resolved to a view name.

@Controller alone is used for traditional MVC apps that return view names (e.g., Thymeleaf templates); to return data directly from a @Controller method you would need to add @ResponseBody on every method. @RestController applies that behavior class-wide, which is why it's the standard choice for building REST APIs.

@RestController
@RequestMapping("/api/users")
public class UserController {
    @GetMapping("/{id}")
    public User getUser(@PathVariable Long id) {
        return userService.findById(id);
    }
}