feat: 기수관리를 위한 엔티티, 서비스, 레포지토리 생성 및 대응하는 에러코드 추가 (DASOMBE-16)

Author: junjinyun

src/main/java/dmu/dasom/api/domain/common/exception/ErrorCode.java

@@ -37,8 +37,8 @@ public enum ErrorCode {
     FILE_ENCODE_FAIL(400, "C028", "파일 인코딩에 실패하였습니다."),
     RECRUITMENT_NOT_ACTIVE(400, "C029", "모집 기간이 아닙니다."),
     NOT_FOUND_PARTICIPANT(400, "C030", "참가자를 찾을 수 없습니다."),
-    EXECUTIVE_NOT_FOUND(400, "C031", "임원진을 찾을 수 없습니다."),
-    ;
+    GENERATION_NOT_FOUND(400, "C031", "저장된 기수를 찾을 수 없습니다."),
+    INVALID_GENERATION_FORMAT(400, "C032", "유효하지 않은 기수 형식입니다. (예: '1기')");
 
     private final int status;
     private final String code;

src/main/java/dmu/dasom/api/global/generation/entity/Generation.java

@@ -0,0 +1,26 @@
+package dmu.dasom.api.global.generation.entity;
+
+import jakarta.persistence.*;
+import lombok.*;
+import org.hibernate.annotations.DynamicUpdate;
+
+@AllArgsConstructor
+@Builder
+@DynamicUpdate
+@Entity
+@Getter
+@NoArgsConstructor
+public class Generation {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id; // 기본키
+
+    @Column(nullable = false, unique = true, length = 10)
+    private String generation; // 기수 (예: "1기", "2기")
+
+
+    public void updateGeneration(String generation) {
+        this.generation = generation;
+    }
+}

src/main/java/dmu/dasom/api/global/generation/repository/GenerationRepository.java

@@ -0,0 +1,12 @@
+package dmu.dasom.api.global.generation.repository;
+
+import dmu.dasom.api.global.generation.entity.Generation;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface GenerationRepository extends JpaRepository<Generation, Long> {
+
+    // 가장 최근 기수 1개 조회
+    Optional<Generation> findFirstByOrderByIdDesc();
+}

src/main/java/dmu/dasom/api/global/generation/service/GenerationService.java

@@ -0,0 +1,61 @@
+package dmu.dasom.api.global.generation.service;
+
+import dmu.dasom.api.domain.common.exception.CustomException;
+import dmu.dasom.api.domain.common.exception.ErrorCode;
+import dmu.dasom.api.global.generation.entity.Generation;
+import dmu.dasom.api.global.generation.repository.GenerationRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.regex.Pattern;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+public class GenerationService {
+
+    private final GenerationRepository generationRepository;
+
+    // 기본값 해당 변수로 관리
+    private static final String DEFAULT_GENERATION = "34기";
+
+    // 정규식: 숫자 + "기" 형식 (예: "1기", "12기")
+    private static final Pattern GENERATION_PATTERN = Pattern.compile("^[0-9]+기$");
+
+    //현재 저장된 기수 조회
+    public String getCurrentGeneration() {
+        try {
+            return generationRepository.findFirstByOrderByIdDesc()
+                    .map(Generation::getGeneration)
+                    .orElseGet(() -> {
+                        log.warn("저장된 기수 없음, 기본값 사용: {}", DEFAULT_GENERATION);
+                        return DEFAULT_GENERATION;
+                    });
+        } catch (Exception e) {
+            throw new CustomException(ErrorCode.INTERNAL_SERVER_ERROR);
+        }
+    }
+
+    //새로운 기수 저장 또는 기존 기수 수정 (유효성 검사 포함)
+    @Transactional
+    public void saveOrUpdateGeneration(String generationValue) {
+        if (!GENERATION_PATTERN.matcher(generationValue).matches()) {
+            throw new CustomException(ErrorCode.INVALID_GENERATION_FORMAT);
+        }
+
+        try {
+            Generation generation = generationRepository.findFirstByOrderByIdDesc()
+                    .orElseGet(() -> Generation.builder().build());
+
+            generation.updateGeneration(generationValue);
+            generationRepository.save(generation);
+
+        } catch (Exception e) {
+            throw new CustomException(ErrorCode.WRITE_FAIL);
+        }
+    }
+
+}