Merge pull request #70 from Korea-Certified-Store/refactor/refactor-s…

…torecertification-api(#69)

가게 조회 API 성능 개선 (#69)

src/main/java/com/nainga/nainga/domain/storecertification/api/StoreCertificationApi.java

@@ -45,7 +45,7 @@ public class StoreCertificationApi {
     @GetMapping("api/v1/storecertification/byLocation")
     public Result<List<StoreCertificationsByLocationResponse>> findStoreCertificationsByLocation(@RequestParam("nwLong") double nwLong, @RequestParam("nwLat") double nwLat, @RequestParam("swLong") double swLong, @RequestParam("swLat") double swLat, @RequestParam("seLong") double seLong, @RequestParam("seLat") double seLat, @RequestParam("neLong") double neLong, @RequestParam("neLat") double neLat) {
         List<StoreCertification> storeCertificationsByLocation = storeCertificationService.findStoreCertificationsByLocation(new Location(nwLong, nwLat), new Location(swLong, swLat), new Location(seLong, seLat), new Location(neLong, neLat));
-        List<Long> storeIdsWithMultipleCertifications = storeCertificationService.findStoreIdsWithMultipleCertifications(); //여러 인증제를 가지고 있는 가게의 id 리스트
+        List<Long> storeIdsWithMultipleCertifications = storeCertificationService.getDuplicatedStoreIds(); //여러 인증제를 가지고 있는 가게의 id 리스트
         List<StoreCertificationsByLocationResponse> storeCertificationsByLocationResponses = new ArrayList<>(); //반환해줄 StoreCertificationsByLocationResponse들의 List
         Map<Long, StoreCertificationsByLocationResponse> map = new HashMap<>(); //여러 인증제를 가지고 있는 가게들의 response를 임시로 저장하고 있을 map
 

src/main/java/com/nainga/nainga/domain/storecertification/application/StoreCertificationService.java

@@ -3,35 +3,49 @@
 import com.nainga.nainga.domain.store.domain.Location;
 import com.nainga.nainga.domain.storecertification.dao.StoreCertificationRepository;
 import com.nainga.nainga.domain.storecertification.domain.StoreCertification;
+import jakarta.annotation.PostConstruct;
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.stream.Collectors;
 
 @Service
 @Transactional(readOnly = true)
-@RequiredArgsConstructor
 public class StoreCertificationService {
     private final StoreCertificationRepository storeCertificationRepository;
-    public List<StoreCertification> findStoreCertificationsByLocation(Location northWestLocation, Location southWestLocation, Location southEastLocation, Location northEastLocation) {
-        return storeCertificationRepository.findStoreCertificationsByLocation(northWestLocation, southWestLocation, southEastLocation, northEastLocation);
+    private List<Long> duplicatedStoreIds;  //여러 인증제를 가지는 중복된 storeId를 담고있는 리스트
+
+    @Autowired
+    public StoreCertificationService(StoreCertificationRepository storeCertificationRepository) {
+        this.storeCertificationRepository = storeCertificationRepository;
     }
 
-    public List<Long> findStoreIdsWithMultipleCertifications() {
+    @PostConstruct
+    public void init() {    //이 Service Bean이 생성된 이후에 한번만 중복된 storeId를 검사해서 Globally하게 저장
         List<StoreCertification> allStoreCertifications = storeCertificationRepository.findAll();   //중복된 id를 검사하기 위함
-        List<Long> allStoreIds = new ArrayList<>();
+
+        HashSet<Long> uniqueStoreIds = new HashSet<>(); //조회 성능을 높이기 위해 HashSet으로 저장
+        HashSet<Long> duplicatedIds = new HashSet<>();
+
         for (StoreCertification storeCertification : allStoreCertifications) {
-            allStoreIds.add(storeCertification.getStore().getId());
+            Long storeId = storeCertification.getStore().getId();
+            if (!uniqueStoreIds.add(storeId)) { //HashSet에 add를 했을 때 이미 존재하는 데이터면 false가 리턴되는 것을 활용
+                duplicatedIds.add(storeId);
+            }
         }
+        duplicatedStoreIds = new ArrayList<>(duplicatedIds);
+    }
 
-        List<Long> duplicatedIds = allStoreIds.stream()
-                .filter(e -> allStoreIds.indexOf(e) != allStoreIds.lastIndexOf(e))  //중복된 StoreId가 있는 경우
-                .distinct() //해당 id를 모아서 1번씩만(중복 제거) 리스트에 담아 전달
-                .collect(Collectors.toList());
+    public List<StoreCertification> findStoreCertificationsByLocation(Location northWestLocation, Location southWestLocation, Location southEastLocation, Location northEastLocation) {
+        return storeCertificationRepository.findStoreCertificationsByLocation(northWestLocation, southWestLocation, southEastLocation, northEastLocation);
+    }
 
-        return duplicatedIds;
+    public List<Long> getDuplicatedStoreIds() {
+        return duplicatedStoreIds;
     }
 }