A controller for a Game Service

Question

I have a Spring MVC controller but I'm not sure that it is a good or bad design. As far as I know, api versioning is missing but apart from that I implemented Swagger for documentation and added SpringSecurity and tried to follow YARAS(Yet Another RESTful API Standard) to build it but I need another eye on that to comment it.

@Slf4j
@Controller
@RequestMapping
@RequiredArgsConstructor
public class XGameController implements GameController {

    private final GameService gameService;

    private final ObjectMapper mapper;

    @RequestMapping(value = "/", method= RequestMethod.GET)
    public String index() {
        return "game";
    }

    @RequestMapping(value = "/login", method= RequestMethod.GET)
    public String login() {
        return "login";
    }

    @Secured("ROLE_USER")
    @RequestMapping(value = "/games", method= RequestMethod.POST)
    public String initializeGame(Model model) {
        log.info("New XGame is initializing...");
        Game game = new Game();
        game = gameService.initializeGame(game.getId());

        try {
            model.addAttribute("game", mapper.writeValueAsString(game));
        } catch (JsonProcessingException e) {
            log.error(e.getMessage());
        }
        log.info("New XGame is initialized successfully!");
        return "game";
    }

    @Secured("ROLE_USER")
    @RequestMapping(value = "/games/{gameId}", method= RequestMethod.PUT)
    public @ResponseBody Game play(@PathVariable("gameId") String gameId,
                                   @RequestParam Integer pitNumber,
                                   @RequestParam String action) {
        log.info("Sowing stone is triggered...");
        return gameService.executeGameRules(UUID.fromString(gameId), pitNumber);
    }

    @RequestMapping(value = "/403", method= RequestMethod.GET)
    public String error403() {
        return "/error/403";
    }

}

My swagger snapshot;

Answer 1

I like to work with the request specific annotation. Also, you don't need @RequestMapping, unless you want to version your API with URL versioning or have some fixed path for all your endpoints.

@Slf4j
@Controller
@RequiredArgsConstructor
public class XGameController implements GameController {

    private final GameService gameService;

    private final ObjectMapper mapper;

    @GetMapping
    public String index() {
        return "game";
    }

    @GetMapping("/login")
    public String login() {
        return "login";
    }

    @Secured("ROLE_USER")
    @PostMapping("/games")
    public String initializeGame(Model model) {
        log.info("New XGame is initializing...");
        Game game = new Game();
        game = gameService.initializeGame(game.getId());

        try {
            model.addAttribute("game", mapper.writeValueAsString(game));
        } catch (JsonProcessingException e) {
            log.error(e.getMessage());
        }
        log.info("New XGame is initialized successfully!");
        return "game";
    }

    @Secured("ROLE_USER")
    @PutMapping("/games/{gameId}")
    public @ResponseBody
    Game play(@PathVariable("gameId") String gameId,
              @RequestParam Integer pitNumber,
              @RequestParam String action) {
        log.info("Sowing stone is triggered...");
        return gameService.executeGameRules(UUID.fromString(gameId), pitNumber);
    }
}

I would create a separate Controller for error handling:

@Controller
public class CustomErrorController implements ErrorController {

    @RequestMapping("/error")
    public String handleError(HttpServletRequest request) {
        Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
        if (status != null) {
            int statusCode = Integer.parseInt(status.toString());
            if (statusCode == HttpStatus.NOT_FOUND.value()) {
                return "404";
            } else if (statusCode == HttpStatus.INTERNAL_SERVER_ERROR.value()) {
                return "500";
            } else if (statusCode == HttpStatus.FORBIDDEN.value()) {
                return "403";
            }
        }
        return "error";
    }
}

When using Spring Boot you don't even need a controller, because Spring will look for specific error pages (like 403.html) in src/main/resources/templates/error/ before defaulting to the generic error.html page whenever your application encounters an error or exception.