fix[poll]:투표하기 예외처리 추가

Author: GarakChoi

backend/src/main/java/com/ai/lawyer/domain/poll/controller/PollController.java

@@ -155,12 +155,7 @@ public ResponseEntity<ApiResponse<List<PollDto>>> getClosedPolls() {
     public ResponseEntity<ApiResponse<PollVoteDto>> voteByIndex(@PathVariable Long pollId, @RequestParam int index) {
         Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
         Long memberId = Long.parseLong(authentication.getName());
-        List<PollOptions> options = pollService.getPollOptions(pollId);
-        if (index < 1 || index > options.size()) {
-            throw new ResponseStatusException(org.springframework.http.HttpStatus.BAD_REQUEST, "index가 옵션 범위를 벗어났습니다.");
-        }
-        Long pollItemsId = options.get(index - 1).getPollItemsId();
-        PollVoteDto result = pollService.vote(pollId, pollItemsId, memberId);
+        PollVoteDto result = pollService.voteByIndex(pollId, index, memberId);
         return ResponseEntity.ok(new ApiResponse<>(200, "투표가 성공적으로 완료되었습니다.", result));
     }
 

backend/src/main/java/com/ai/lawyer/domain/poll/service/PollService.java

@@ -28,6 +28,7 @@ public interface PollService {
 
     // ===== 투표 관련 =====
     PollVoteDto vote(Long pollId, Long pollItemsId, Long memberId);
+    PollVoteDto voteByIndex(Long pollId, int index, Long memberId);
 
     // ===== 투표 취소 관련 =====
     void cancelVote(Long pollId, Long memberId);

backend/src/main/java/com/ai/lawyer/domain/poll/service/PollServiceImpl.java

@@ -156,6 +156,19 @@ public PollVoteDto vote(Long pollId, Long pollItemsId, Long memberId) {
                 .build();
     }
 
+    @Override
+    public PollVoteDto voteByIndex(Long pollId, int index, Long memberId) {
+        List<PollOptions> options = getPollOptions(pollId);
+        if (options == null || options.isEmpty()) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "투표 항목이 존재하지 않습니다.");
+        }
+        if (index < 1 || index > options.size()) {
+            throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "index가 옵션 범위를 벗어났습니다.");
+        }
+        Long pollItemsId = options.get(index - 1).getPollItemsId();
+        return vote(pollId, pollItemsId, memberId);
+    }
+
     @Override
     public PollStaticsResponseDto getPollStatics(Long pollId) {
         if (!pollRepository.existsById(pollId)) {