🧭 Spring 입문 & 로드맵 완전 가이드

@RestController
@RequestMapping("/api/greetings")
public class GreetingController {

    private final GreetingService greetingService;

    // 생성자 주입: Spring이 GreetingService Bean을 찾아 넣어준다
    public GreetingController(GreetingService greetingService) {
        this.greetingService = greetingService;
    }

    @GetMapping("/{name}")
    public GreetingResponse greet(@PathVariable String name) {
        return greetingService.greet(name);
    }
}

@Service
class GreetingService {
    GreetingResponse greet(String name) {
        return new GreetingResponse("안녕하세요, " + name + "님!");
    }
}

record GreetingResponse(String message) {}