[리팩토링] EntityManager → QueryDSL을 이용한 getCategories

✅ 이전 버전은..

1. 앞서 entitymanager를 직접 불러와 사용하는것 
2. 레포지토리르 2개나 만들어 사용한것 (서비스에 2개의 의존 레포지토리가 생겼다)

 

https://jie0025.tistory.com/345

[Springboot][개발] FLAG - Category CRUD 1차 완성 (Merged)

 

 

 

예전에 스터디하면서 정리해놓은 글이 있어 해당 사용방법을 참고했다.

https://jie0025.tistory.com/254

[Spring] QueryDSL

 

---

 

✅ QueryDSL을 이용한 리팩토링

 

💻 CategoryRepositoryImpl

package com.FlagHome.backend.v1.category.repository;

import com.FlagHome.backend.v1.category.entity.Category;
import com.FlagHome.backend.v1.category.entity.QCategory;
import com.querydsl.jpa.impl.JPAQueryFactory;
import lombok.RequiredArgsConstructor;

import java.util.List;

@RequiredArgsConstructor
public class CategoryRepositoryImpl implements CategoryRepositoryCustom{

    private final JPAQueryFactory queryFactory;

    @Override
    public List<Category> findAll(){
        QCategory category = QCategory.category;
        List<Category> result = queryFactory
                .select(category)
                .from(category)
                .where(category.parent.isNull())
                .fetch();

        return result;
    }
}

 

💻 CategoryRepositoryCustom

package com.FlagHome.backend.v1.category.repository;

import com.FlagHome.backend.v1.category.entity.Category;

import java.util.List;

public interface CategoryRepositoryCustom {
    List<Category> findAll();
}

 

💻 CategoryRepository

package com.FlagHome.backend.v1.category.repository;

import com.FlagHome.backend.v1.category.entity.Category;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface CategoryRepository extends JpaRepository<Category,Long>, CategoryRepositoryCustom {

}

 

💻 CategoryResultDto

package com.FlagHome.backend.v1.category.dto;


import com.FlagHome.backend.v1.category.entity.Category;
import lombok.AllArgsConstructor;
import lombok.Getter;
import lombok.NoArgsConstructor;

import java.util.List;
import java.util.stream.Collectors;

@Getter
@AllArgsConstructor
@NoArgsConstructor
public class CategoryResultDto {
    private Long id;
    private String name;
    private Long depth;
    private List<CategoryResultDto> children;

    public static CategoryResultDto of(Category category) {
        return new CategoryResultDto(
                category.getId(),
                category.getName(),
                category.getCategoryDepth(),
                category.getChildren().stream().map(CategoryResultDto::of).collect(Collectors.toList())
        );
    }
}

 

💻 CategoryService

@Service
@RequiredArgsConstructor
public class CategoryService {
    private CategoryRepository categoryRepository;
    
    @Transactional
    public List<CategoryResultDto> getCategories () {

        List<CategoryResultDto> categories = categoryRepository
                .findAll().stream().map(CategoryResultDto::of)
                .collect(Collectors.toList());

        return categories;
    }

 
}

 

 

✅ 동작확인

이전과 정확하게 똑같이 동작하는것을 확인했다.