Sawijining endpoint REST ing Spring Boot iku metode ing @RestController, sing dipetakan menyang verba lan path HTTP. @RestController = @Controller + @ResponseBody, mula nilai balikan langsung diserialisasi menyang badan respons (JSON liwat Jackson) tinimbang diresolve dadi tampilan.
@RestController
@RequestMapping("/api/users") // base path for every method below
public class UserController {
private final UserService service;
public UserController(UserService service) { this.service = service; }
@GetMapping("/{id}") // GET /api/users/42
public UserDto get(@PathVariable Long id) { // bind {id} from the URL
return service.findById(id); // returned object -> JSON
}
@PostMapping // POST /api/users
@ResponseStatus(HttpStatus.CREATED) // 201 instead of 200
public UserDto create(@Valid @RequestBody UserDto body) { // JSON -> object
return service.create(body);
}
@GetMapping // GET /api/users?role=admin
public List<UserDto> list(@RequestParam(required = false) String role) {
return service.findByRole(role);
}
}
Anotasi kunci: @PathVariable narik nilai saka path, @RequestParam maca parameter query-string, lan @RequestBody ndeserialisasi payload JSON. Nambah @Valid micu Bean Validation (@NotNull, @Email…) ing DTO sing mlebu sadurunge metode-mu mlaku.
@GetMapping("/{id}")
public ResponseEntity<UserDto> get(@PathVariable Long id) {
return service.find(id)
.map(ResponseEntity::ok) // 200 + body
.orElse(ResponseEntity.notFound().build()); // 404, no body
}
Iki gawean backend sadina-dina, mula pewawancara ngarepake kelancaran. Jawaban sing kuat nyebut nganggo DTO tinimbang ngetokake entitas JPA, validasi input nganggo @Valid, lan mbalekake kode status sing bener nganggo ResponseEntity — beda antara endpoint dolanan lan API nyata.
Pustaka pitakon wawancara IT kanthi jawaban rinci — saka Junior nganti Senior.
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