feat: exception handling (#34)

* feat: 전역 예외 핸들러 추가

* feat: ErrorResponse 추가

* feat: ErrorCode 추가

* feat: CustomException 추가

* feat: JwtFilter의 예외 처리 필터 추가

* refactor: 토큰 파싱 과정의 예외를 CustomException으로 변경

* remove: CustomException 던지므로 throws 제거

* refactor: parseAccessToken 내부에서 CustomException 던지므로 try-catch 제거

* typo: 오타 수정

* feat: Jwt 관련 ErrorCode 추가

* feat: JwtFilter의 예외 처리 필터 추가

* fix: 재발급 메서드에서 잡을 수 있도록 수정

* fix: try-catch로 만료 토큰의 경우 null을 반환

* fix: 토큰 조회 메서드 수정

기존 메서드는 데이터의 유무와 무관하게 항상 비어있는 Optional을 반환함.

사용하지 않는 Repository의 메서드는 제거함.

* fix: refreshToken을 accessToken으로 수정

accessToken을 받아야 하는 메서드인데 refreshToken을 받고 있었음.

src/main/java/com/gdschongik/gdsc/domain/auth/application/JwtService.java

@@ -44,7 +44,7 @@ private void saveRefreshTokenToRedis(RefreshTokenDto refreshTokenDto) {
     public AccessTokenDto retrieveAccessToken(String accessTokenValue) {
         try {
             return jwtUtil.parseAccessToken(accessTokenValue);
-        } catch (Exception e) {
+        } catch (ExpiredJwtException e) {
             return null;
         }
     }
@@ -71,7 +71,7 @@ public RefreshTokenDto retrieveRefreshToken(String refreshTokenValue) {
 
     private Optional<RefreshToken> getRefreshTokenFromRedis(Long memberId) {
         // TODO: CustomException으로 바꾸기
-        return refreshTokenRepository.findByMemberId(memberId);
+        return refreshTokenRepository.findById(memberId);
     }
 
     private RefreshTokenDto parseRefreshToken(String refreshTokenValue) {

src/main/java/com/gdschongik/gdsc/domain/auth/dao/RefreshTokenRepository.java

@@ -1,9 +1,6 @@
 package com.gdschongik.gdsc.domain.auth.dao;
 
 import com.gdschongik.gdsc.domain.auth.domain.RefreshToken;
-import java.util.Optional;
 import org.springframework.data.repository.CrudRepository;
 
-public interface RefreshTokenRepository extends CrudRepository<RefreshToken, Long> {
-    Optional<RefreshToken> findByMemberId(Long aLong);
-}
+public interface RefreshTokenRepository extends CrudRepository<RefreshToken, Long> {}

src/main/java/com/gdschongik/gdsc/global/config/WebSecurityConfig.java

@@ -2,10 +2,12 @@
 
 import static org.springframework.security.config.Customizer.*;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.gdschongik.gdsc.domain.auth.application.JwtService;
 import com.gdschongik.gdsc.domain.member.dao.MemberRepository;
 import com.gdschongik.gdsc.global.security.CustomSuccessHandler;
 import com.gdschongik.gdsc.global.security.CustomUserService;
+import com.gdschongik.gdsc.global.security.JwtExceptionFilter;
 import com.gdschongik.gdsc.global.security.JwtFilter;
 import com.gdschongik.gdsc.global.util.CookieUtil;
 import lombok.RequiredArgsConstructor;
@@ -26,6 +28,7 @@ public class WebSecurityConfig {
     private final MemberRepository memberRepository;
     private final JwtService jwtService;
     private final CookieUtil cookieUtil;
+    private final ObjectMapper objectMapper;
 
     @Bean
     public SecurityFilterChain filterChain(HttpSecurity httpSecurity) throws Exception {
@@ -41,6 +44,7 @@ public SecurityFilterChain filterChain(HttpSecurity httpSecurity) throws Excepti
                         .successHandler(customSuccessHandler(jwtService, cookieUtil)));
 
         httpSecurity.addFilterBefore(jwtFilter(jwtService, cookieUtil), UsernamePasswordAuthenticationFilter.class);
+        httpSecurity.addFilterBefore(jwtExceptionFilter(objectMapper), JwtFilter.class);
 
         return httpSecurity.build();
     }
@@ -59,4 +63,9 @@ public CustomSuccessHandler customSuccessHandler(JwtService jwtService, CookieUt
     public JwtFilter jwtFilter(JwtService jwtService, CookieUtil cookieUtil) {
         return new JwtFilter(jwtService, cookieUtil);
     }
+
+    @Bean
+    public JwtExceptionFilter jwtExceptionFilter(ObjectMapper objectMapper) {
+        return new JwtExceptionFilter(objectMapper);
+    }
 }

src/main/java/com/gdschongik/gdsc/global/exception/CustomException.java

@@ -0,0 +1,14 @@
+package com.gdschongik.gdsc.global.exception;
+
+import lombok.Getter;
+
+@Getter
+public class CustomException extends RuntimeException {
+
+    private final ErrorCode errorCode;
+
+    public CustomException(ErrorCode errorCode) {
+        super(errorCode.getMessage());
+        this.errorCode = errorCode;
+    }
+}

src/main/java/com/gdschongik/gdsc/global/exception/ErrorCode.java

@@ -0,0 +1,18 @@
+package com.gdschongik.gdsc.global.exception;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+@AllArgsConstructor
+public enum ErrorCode {
+    INTERNAL_SERVER_ERROR(HttpStatus.INTERNAL_SERVER_ERROR, "서버 에러입니다."),
+
+    // Jwt
+    INVALID_JWT_TOKEN(HttpStatus.UNAUTHORIZED, "유효하지 않은 JWT 토큰입니다."),
+    EXPIRED_JWT_TOKEN(HttpStatus.UNAUTHORIZED, "만료된 JWT 토큰입니다.");
+
+    private final HttpStatus status;
+    private final String message;
+}

src/main/java/com/gdschongik/gdsc/global/exception/ErrorResponse.java

@@ -0,0 +1,7 @@
+package com.gdschongik.gdsc.global.exception;
+
+public record ErrorResponse(String errorCodeName, String errorMessage) {
+    public static ErrorResponse of(ErrorCode errorCode) {
+        return new ErrorResponse(errorCode.name(), errorCode.getMessage());
+    }
+}

src/main/java/com/gdschongik/gdsc/global/exception/GlobalExceptionHandler.java

@@ -0,0 +1,25 @@
+package com.gdschongik.gdsc.global.exception;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+@Slf4j
+@RestControllerAdvice
+public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler(CustomException.class)
+    public ResponseEntity<ErrorResponse> handleCustomException(CustomException e) {
+        log.error("CustomException : {}", e.getMessage(), e);
+        return ResponseEntity.status(e.getErrorCode().getStatus()).body(ErrorResponse.of(e.getErrorCode()));
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ErrorResponse> handleException(Exception e) {
+        log.error("INTERNAL_SERVER_ERROR : {}", e.getMessage(), e);
+        return ResponseEntity.status(ErrorCode.INTERNAL_SERVER_ERROR.getStatus())
+                .body(ErrorResponse.of(ErrorCode.INTERNAL_SERVER_ERROR));
+    }
+}

src/main/java/com/gdschongik/gdsc/global/security/JwtExceptionFilter.java

@@ -0,0 +1,34 @@
+package com.gdschongik.gdsc.global.security;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.gdschongik.gdsc.global.exception.CustomException;
+import com.gdschongik.gdsc.global.exception.ErrorResponse;
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+@Slf4j
+@RequiredArgsConstructor
+public class JwtExceptionFilter extends OncePerRequestFilter {
+
+    private final ObjectMapper objectMapper;
+
+    @Override
+    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
+            throws ServletException, IOException {
+        try {
+            filterChain.doFilter(request, response);
+        } catch (CustomException e) {
+            log.error("JWTException : {}", e.getMessage(), e);
+            response.setCharacterEncoding("UTF-8");
+            response.setContentType("application/json");
+            response.setStatus(e.getErrorCode().getStatus().value());
+            response.getWriter().write(objectMapper.writeValueAsString(ErrorResponse.of(e.getErrorCode())));
+        }
+    }
+}

src/main/java/com/gdschongik/gdsc/global/security/JwtFilter.java

@@ -50,7 +50,7 @@ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse
         }
 
         Optional<AccessTokenDto> reissueAccessToken =
-                Optional.ofNullable(jwtService.reissueAccessTokenIfExpired(refreshTokenValue));
+                Optional.ofNullable(jwtService.reissueAccessTokenIfExpired(accessTokenValue));
         RefreshTokenDto refreshTokenDto = jwtService.retrieveRefreshToken(refreshTokenValue);
 
         // AT가 만료되었고, RT가 유효하면 AT, RT 재발급

src/main/java/com/gdschongik/gdsc/global/util/JwtUtil.java

@@ -6,6 +6,8 @@
 import com.gdschongik.gdsc.domain.auth.dto.RefreshTokenDto;
 import com.gdschongik.gdsc.domain.member.domain.MemberRole;
 import com.gdschongik.gdsc.global.common.constant.JwtConstant;
+import com.gdschongik.gdsc.global.exception.CustomException;
+import com.gdschongik.gdsc.global.exception.ErrorCode;
 import com.gdschongik.gdsc.global.property.JwtProperty;
 import io.jsonwebtoken.Claims;
 import io.jsonwebtoken.ExpiredJwtException;
@@ -83,7 +85,7 @@ public AccessTokenDto parseAccessToken(String accessTokenValue) throws ExpiredJw
         } catch (ExpiredJwtException e) {
             throw e;
         } catch (Exception e) {
-            return null;
+            throw new CustomException(ErrorCode.INVALID_JWT_TOKEN);
         }
     }