[Fix] 챕터 보상 수령 처리 API 요청을 두 번 이상 보낼 수 있는 문제를 해결했습니다.

common/src/main/java/com/codingland/common/exception/chapter/HasReceivedRewardErrorCode.java

@@ -0,0 +1,22 @@
+package com.codingland.common.exception.chapter;
+
+import com.codingland.common.common.ApplicationResponse;
+import com.codingland.common.common.BaseErrorCode;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+@AllArgsConstructor
+public enum HasReceivedRewardErrorCode implements BaseErrorCode {
+    ALREADY_EXIST(HttpStatus.BAD_REQUEST, "2000", "챕터 보상을 이미 받았습니다.")
+    ;
+    private final HttpStatus httpStatus;
+    private final String code;
+    private final String message;
+
+    @Override
+    public ApplicationResponse<String> getErrorResponse() {
+        return ApplicationResponse.server(code, message);
+    }
+}

common/src/main/java/com/codingland/common/exception/chapter/HasReceivedRewardException.java

@@ -0,0 +1,15 @@
+package com.codingland.common.exception.chapter;
+
+import com.codingland.common.common.BaseErrorCode;
+import lombok.Getter;
+
+@Getter
+public class HasReceivedRewardException extends RuntimeException {
+    private final BaseErrorCode errorCode;
+    private final Throwable cause;
+
+    public HasReceivedRewardException(BaseErrorCode errorCode) {
+        this.errorCode = errorCode;
+        this.cause = null;
+    }
+}

domain/src/main/java/com/codingland/domain/chapter/service/HasReceivedRewardService.java

@@ -1,7 +1,6 @@
 package com.codingland.domain.chapter.service;
 
-import com.codingland.common.exception.chapter.ChapterErrorCode;
-import com.codingland.common.exception.chapter.ChapterException;
+import com.codingland.common.exception.chapter.*;
 import com.codingland.common.exception.user.UserErrorCode;
 import com.codingland.common.exception.user.UserException;
 import com.codingland.domain.chapter.entity.Chapter;
@@ -34,6 +33,9 @@ public void processChapterReward(Long chapter_id, Long user_id) {
                 .orElseThrow(() -> new ChapterException(ChapterErrorCode.NOT_FOUND_CHAPTER_ERROR));
         User foundUser = userRepository.findById(user_id)
                 .orElseThrow(() -> new UserException(UserErrorCode.No_USER_INFO));
+        if (hasReceivedRewardRepository.findByChapterAndUser(foundChapter, foundUser).isPresent()) {
+            throw new HasReceivedRewardException(HasReceivedRewardErrorCode.ALREADY_EXIST);
+        }
         HasReceivedReward hasReceivedReward = HasReceivedReward.thisRewardHasReceived(foundChapter, foundUser);
         hasReceivedRewardRepository.save(hasReceivedReward);
     }