feat : 좋아요 누를시 좋아요 수 동시성 문제 해결

src/main/java/kusitms/gallae/repository/program/ProgramRespository.java

@@ -1,9 +1,13 @@
 package kusitms.gallae.repository.program;
 
+import jakarta.persistence.LockModeType;
 import kusitms.gallae.domain.Program;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 import java.util.List;
 import java.util.Optional;
@@ -12,13 +16,9 @@ public interface ProgramRespository extends JpaRepository<Program, Long> {
     @Override
     Optional<Program> findById(Long programId);
 
-    Page<Program> findAllByProgramTypeOrderByCreatedAtDesc(String programType , Pageable pageable);
-
-    Page<Program> findProgramByProgramNameContaining(String programName, Pageable pageable);
-
-    List<Program> findTop4ByOrderByCreatedAtDesc();
-
-    List<Program> findTop4ByOrderByProgramLikeDesc();
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("select p from Program p where p.id = :programId")
+    Optional<Program> findWithIdForUpdate(@Param("programId") Long programId);
 
     Program findByUserIdAndStatus(Long id, Program.ProgramStatus programStatus);
 

src/main/java/kusitms/gallae/service/favorite/FavoriteServiceImpl.java

@@ -57,7 +57,7 @@ public class FavoriteServiceImpl implements FavoriteService {
     @Override
     public void postFavorite(String username, Long programId) {
         User user = userRepository.findById(Long.valueOf(username)).get();
-        Program program = programRespository.findById(programId).get();
+        Program program = programRespository.findWithIdForUpdate(programId).get();
         Favorite favorite = favoriteRepository.findByUserAndProgram(user,program).orElse(null);
         if(favorite == null ) {
             program.setProgramLike(program.getProgramLike() + 1);