feat: 닉네임 및 이메일 중복 방지 기능 추가

src/main/java/cotato/growingpain/auth/controller/AuthController.java

@@ -2,11 +2,14 @@
 
 import cotato.growingpain.auth.dto.request.ChangePasswordRequest;
 import cotato.growingpain.auth.dto.request.CompleteSignupRequest;
+import cotato.growingpain.auth.dto.request.DuplicateCheckRequest;
 import cotato.growingpain.auth.dto.request.LoginRequest;
 import cotato.growingpain.auth.dto.request.LogoutRequest;
 import cotato.growingpain.auth.dto.request.ResetPasswordRequest;
+import cotato.growingpain.auth.dto.response.DuplicateCheckResponse;
 import cotato.growingpain.auth.dto.response.ResetPasswordResponse;
 import cotato.growingpain.auth.service.AuthService;
+import cotato.growingpain.auth.service.ValidateService;
 import cotato.growingpain.common.Response;
 import cotato.growingpain.security.jwt.Token;
 import cotato.growingpain.security.jwt.dto.request.ReissueRequest;
@@ -23,6 +26,7 @@
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestHeader;
@@ -38,6 +42,7 @@
 public class AuthController {
 
     private final AuthService authService;
+    private final ValidateService validateService;
 
     @Operation(summary = "일반 로그인", description = "회원가입 및 로그인을 위한 메소드")
     @ApiResponse(content = @Content(schema = @Schema(implementation = Token.class)))
@@ -94,4 +99,34 @@ public Response<?> changePassword(@RequestBody @Valid ChangePasswordRequest requ
         authService.changePassword(request, memberId);
         return Response.createSuccessWithNoData("비밀번호 변경 완료");
     }
+
+    @Operation(summary = "이메일 중복 검증", description = "회원가입 시 기존 사용자와 이메일이 중복되는지 확인하는 메소드")
+    @ApiResponse(content = @Content(schema = @Schema(implementation = DuplicateCheckResponse.class)))
+    @GetMapping("/validate/email")
+    @ResponseStatus(HttpStatus.OK)
+    public Response<DuplicateCheckResponse> checkDuplicateEmail(@RequestBody DuplicateCheckRequest request) {
+
+        boolean isDuplicate = validateService.isDuplicateEmail(request.value());
+        DuplicateCheckResponse response = new DuplicateCheckResponse(isDuplicate);
+        if (isDuplicate) {
+            return Response.createSuccess("이미 사용 중인 이메일입니다.", response);
+        } else {
+            return Response.createSuccess("사용 가능한 이메일입니다.", response);
+        }
+    }
+
+    @Operation(summary = "닉네임 중복 검증", description = "추가 정보 입력 시 기존 사용자와 닉네임이 중복되는지 확인하는 메소드")
+    @ApiResponse(content = @Content(schema = @Schema(implementation = DuplicateCheckResponse.class)))
+    @GetMapping("/validate/nickname")
+    @ResponseStatus(HttpStatus.OK)
+    public Response<DuplicateCheckResponse> checkDuplicateNickname(@RequestBody DuplicateCheckRequest request) {
+        boolean isDuplicate = validateService.isDuplicateNickname(request.value());
+        DuplicateCheckResponse response = new DuplicateCheckResponse(isDuplicate);
+
+        if (isDuplicate) {
+            return Response.createSuccess("이미 사용 중인 닉네임입니다.", response);
+        } else {
+            return Response.createSuccess("사용 가능한 닉네임입니다.", response);
+        }
+    }
 }

src/main/java/cotato/growingpain/auth/dto/request/DuplicateCheckRequest.java

@@ -0,0 +1,6 @@
+package cotato.growingpain.auth.dto.request;
+
+public record DuplicateCheckRequest(
+        String value
+) {
+}

src/main/java/cotato/growingpain/auth/dto/response/DuplicateCheckResponse.java

@@ -0,0 +1,6 @@
+package cotato.growingpain.auth.dto.response;
+
+public record DuplicateCheckResponse(
+        Boolean isDuplicate
+) {
+}

src/main/java/cotato/growingpain/auth/service/ValidateService.java

@@ -18,7 +18,6 @@ public class ValidateService {
     private static final String PASSWORD_PATTERN = "^(?=.*[A-Za-z])(?=.*\\d)[A-Za-z\\d]{8,16}$";
     private final MemberRepository memberRepository;
 
-
     public void checkPasswordPattern(String password) {
         Pattern pattern = Pattern.compile(PASSWORD_PATTERN);
         Matcher matcher = pattern.matcher(password);
@@ -37,16 +36,24 @@ public boolean isValidPassword(String password) {
     }
 
     public void checkDuplicateNickName(String name) {
-        if (memberRepository.findByName(name).isPresent()) {
+        if (isDuplicateNickname(name)) {
             log.error("[회원 가입 실패]: 존재하는 닉네임 " + name);
             throw new AppException(ErrorCode.NICKNAME_DUPLICATED);
         }
     }
 
     public void checkDuplicateEmail(@NotBlank(message = "로그인 할 아이디를 입력해주세요") String email) {
-        if (memberRepository.findByEmail(email).isPresent()) {
+        if (isDuplicateEmail(email)) {
             log.error("[회원 가입 실패]: 중복된 이메일 " + email);
             throw new AppException(ErrorCode.EMAIL_DUPLICATED);
         }
     }
+
+    public boolean isDuplicateEmail(String email) {
+        return memberRepository.findByEmail(email).isPresent();
+    }
+
+    public boolean isDuplicateNickname(String nickName) {
+        return memberRepository.findByName(nickName).isPresent();
+    }
 }