[feat] 유사칵테일 추천 기능 구현

src/main/java/com/back/domain/cocktail/controller/CocktailRecommendController.java

@@ -0,0 +1,30 @@
+package com.back.domain.cocktail.controller;
+
+import com.back.domain.cocktail.dto.CocktailRecommendResponseDto;
+import com.back.domain.cocktail.service.RecommendService;
+import com.back.global.rsData.RsData;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/cocktails/recommend")
+@Tag(name = "ApiCocktailRecommendController", description = "API 칵테일 추천 컨트롤러")
+@RequiredArgsConstructor
+public class CocktailRecommendController {
+
+    private final RecommendService recommendService;
+
+    // 상세페이지 추천 (DTO로 반환)
+    @Operation(summary = "상세페이지 유사 칵테일 추천", description = "현재 칵테일과 유사한 칵테일 최대 3개를 반환합니다.")
+    @GetMapping("/related")
+    public RsData<List<CocktailRecommendResponseDto>> recommendRelated(@RequestParam Long cocktailId) {
+        return RsData.successOf(recommendService.recommendRelatedCocktails(cocktailId, 3));
+    }
+}

src/main/java/com/back/domain/cocktail/dto/CocktailRecommendResponseDto.java

@@ -0,0 +1,12 @@
+package com.back.domain.cocktail.dto;
+
+public record CocktailRecommendResponseDto(
+        Long id,                  // 상세페이지 이동용 ID
+        String cocktailNameKo,    // 한글 이름
+        String cocktailName,      // 영문 이름
+        String cocktailImgUrl,    // 이미지 URL (썸네일)
+        String alcoholStrength,   // 도수 (라이트/미디엄/스트롱 등)
+        String alcoholBaseType    // 베이스 주종 (진, 럼, 보드카 등)
+) {
+}
+

src/main/java/com/back/domain/cocktail/repository/CocktailRepository.java

@@ -36,4 +36,12 @@ Page<Cocktail> searchWithFilters(@Param("keyword") String keyword,
                                      @Param("types") List<CocktailType> types,
                                      @Param("bases") List<AlcoholBaseType> bases,
                                      Pageable pageable);
+    //유사칵테일 추천관련
+    List<Cocktail> findByAlcoholStrengthAndIdNot(AlcoholStrength strength, Long excludeId);
+
+    //유사칵테일 추천관련
+    List<Cocktail> findByCocktailTypeAndIdNot(CocktailType type, Long excludeId);
+
+    //유사칵테일 추천관련
+    List<Cocktail> findByAlcoholBaseTypeAndIdNot(AlcoholBaseType baseType, Long excludeId);
 }

src/main/java/com/back/domain/cocktail/service/RecommendService.java

@@ -0,0 +1,53 @@
+package com.back.domain.cocktail.service;
+
+import com.back.domain.cocktail.dto.CocktailRecommendResponseDto;
+import com.back.domain.cocktail.entity.Cocktail;
+import com.back.domain.cocktail.repository.CocktailRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+
+@Service
+@RequiredArgsConstructor
+public class RecommendService {
+
+    private final CocktailRepository cocktailRepository;
+
+    public List<CocktailRecommendResponseDto> recommendRelatedCocktails(Long cocktailId, int maxSize) {
+        Cocktail current = cocktailRepository.findById(cocktailId)
+                .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 칵테일입니다."));
+
+        // 3가지 조건으로 유사 칵테일 조회
+        List<Cocktail> byAlcoholStrength = cocktailRepository.findByAlcoholStrengthAndIdNot(current.getAlcoholStrength(), current.getId());
+        List<Cocktail> byCocktailType = cocktailRepository.findByCocktailTypeAndIdNot(current.getCocktailType(), current.getId());
+        List<Cocktail> byAlcoholBase = cocktailRepository.findByAlcoholBaseTypeAndIdNot(current.getAlcoholBaseType(), current.getId());
+
+        // 합치고 중복 제거
+        Set<Cocktail> combined = new LinkedHashSet<>();
+        combined.addAll(byAlcoholStrength);
+        combined.addAll(byCocktailType);
+        combined.addAll(byAlcoholBase);
+
+        List<Cocktail> combinedList = new ArrayList<>(combined);
+        if (combinedList.size() > maxSize) {
+            combinedList = combinedList.subList(0, maxSize);
+        }
+
+        // DTO로 변환
+        return combinedList.stream()
+                .map(c -> new CocktailRecommendResponseDto(
+                        c.getId(),
+                        c.getCocktailNameKo(),
+                        c.getCocktailName(),
+                        c.getCocktailImgUrl(),
+                        c.getAlcoholStrength().name(),
+                        c.getAlcoholBaseType().name()
+                ))
+                .toList();
+    }
+}
+

src/main/java/com/back/global/globalExceptionHandler/GlobalExceptionHandler.java

@@ -156,4 +156,9 @@ public ResponseEntity<RsData<Void>> handleIOException(IOException e) {
                 .body(RsData.of(500, "서버 내부 오류가 발생했습니다.", null));
     }
 
+    @ExceptionHandler(IllegalArgumentException.class)
+    public ResponseEntity<RsData<Void>> handleIllegalArgumentException(IllegalArgumentException ex) {
+        return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                .body(RsData.of(404, ex.getMessage()));
+    }
 }

src/main/resources/data-h2.sql

@@ -1,7 +1,7 @@
 -- 테이블 생성
 CREATE TABLE IF NOT EXISTS cocktail (
-                                        id BIGINT AUTO_INCREMENT PRIMARY KEY,
-                                        cocktail_name VARCHAR(255),
+    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    cocktail_name VARCHAR(255),
     cocktail_name_ko VARCHAR(255),
     alcohol_strength VARCHAR(50),
     cocktail_story CLOB,
@@ -14,7 +14,7 @@ CREATE TABLE IF NOT EXISTS cocktail (
 
 -- CSV 파일에서 데이터 읽어오기
 INSERT INTO cocktail (
-    cocktail_name, cocktail_name_ko, alcohol_strength,
+    cocktail_name,cocktail_name_ko, alcohol_strength,
     cocktail_story, cocktail_type, alcohol_base_type,
     ingredient, recipe, cocktail_img_url
 )