Field 'modelMapper' may be 'final' : final 선언

< SimpleProductService.java >

package kr.co.hanbit.product.management.application;

import kr.co.hanbit.product.management.domain.Product;
import kr.co.hanbit.product.management.infrastructure.ListProductRepository;
import kr.co.hanbit.product.management.presentation.ProductDto;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class SimpleProductService {
    
    private ListProductRepository listProductRepository; // 에러 1
    private ModelMapper modelMapper; // 에러 2
    
    @Autowired
    SimpleProductService(ListProductRepository listProductRepository, ModelMapper modelMapper) {
        this.listProductRepository = listProductRepository;
        this.modelMapper = modelMapper;
    }
    
    public ProductDto add(ProductDto productDto) {
        //1. ProductDto를 Product로 변환하는 코드
        Product product = modelMapper.map(productDto, Product.class);
        
        //2. 레포지토리를 호출하는 코드
        Product savedProduct = listProductRepository.add(product);
        
        //3. Product를 ProductDTO로 변환하는 코드
        ProductDto savedProductDto = modelMapper.map(savedProduct, ProductDto.class);
        
        //4. DTO를 반환하는 코드
        return savedProductDto;
    }
    
    public ProductDto findById(Long id) {
        Product product = listProductRepository.findById(id);
        ProductDto productDto = modelMapper.map(product, ProductDto.class);
        return productDto;
    }
    
    public List<ProductDto> findAll() {
        List<Product> products = listProductRepository.findAll();
        List<ProductDto> productDtos = products.stream()
                .map(product -> modelMapper.map(product, ProductDto.class))
                .toList();
        return productDtos;
    }
    
    public List<ProductDto> findByNameContaining(String name) {
        List<Product> products = listProductRepository.findByNameContaining(name);
        List<ProductDto> productDtos = products.stream()
                .map(product -> modelMapper.map(product, ProductDto.class))
                .toList();
        return productDtos;
    }
}

표시된 부분에서 각각의 에러가 발생하였다.

Field 'listProductRepository' may be 'final'.
Field 'modelMapper' may be 'final'.

 

노란줄 너무 거슬리쟈나 ...🥺

 

해당 에러는 listProductRepository와 modelMapper 필드가 초기화된 후 변경되지 않을 경우,

해당 필드를 final로 선언할 수 있다는 의미이다.

 

• 객체의 불변성 높여줄 수 있음.
• 코드의 안정성 개선 가능.

위와 같은 장점을 줄 수 있기 때문에,

final로 선언하면 된다.

---

< SimpleProductService.java > 수정본

package kr.co.hanbit.product.management.application;

import kr.co.hanbit.product.management.domain.Product;
import kr.co.hanbit.product.management.infrastructure.ListProductRepository;
import kr.co.hanbit.product.management.presentation.ProductDto;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class SimpleProductService {
    
    private final ListProductRepository listProductRepository; // 수정 1
    private final ModelMapper modelMapper; // 수정 2
    
    @Autowired
    SimpleProductService(ListProductRepository listProductRepository, ModelMapper modelMapper) {
        this.listProductRepository = listProductRepository;
        this.modelMapper = modelMapper;
    }
    
    public ProductDto add(ProductDto productDto) {
        //1. ProductDto를 Product로 변환하는 코드
        Product product = modelMapper.map(productDto, Product.class);
        
        //2. 레포지토리를 호출하는 코드
        Product savedProduct = listProductRepository.add(product);
        
        //3. Product를 ProductDTO로 변환하는 코드
        ProductDto savedProductDto = modelMapper.map(savedProduct, ProductDto.class);
        
        //4. DTO를 반환하는 코드
        return savedProductDto;
    }
    
    public ProductDto findById(Long id) {
        Product product = listProductRepository.findById(id);
        ProductDto productDto = modelMapper.map(product, ProductDto.class);
        return productDto;
    }
    
    public List<ProductDto> findAll() {
        List<Product> products = listProductRepository.findAll();
        List<ProductDto> productDtos = products.stream()
                .map(product -> modelMapper.map(product, ProductDto.class))
                .toList();
        return productDtos;
    }
    
    public List<ProductDto> findByNameContaining(String name) {
        List<Product> products = listProductRepository.findByNameContaining(name);
        List<ProductDto> productDtos = products.stream()
                .map(product -> modelMapper.map(product, ProductDto.class))
                .toList();
        return productDtos;
    }
}