[Spring boot] DAO 연동을 위한 컨트롤러와 서비스 설계

서비스 클래스 만들기

• 서비스 레이어에서는 도메인 모델을 활용해 애플리케이션에서 제공하는 핵심 기능 제공

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Data
@NoArgsConstructor
@ToString
@Builder
public class ProductDto {

    private String name;

    private int price;

    private int stock;

    public ProductDto(String name, int price, int stock) {
        this.name = name;
        this.price = price;
        this.stock = stock;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public int getStock() {
        return stock;
    }

    public void setStock(int stock) {
        this.stock = stock;
    }

}

• 서비스 인터페이스 작성
• 기본적인 CRUD의 기능을 호출하기 위해 간단하게 메서드 정의

import Dto.ProductDto;
import Dto.ProductResponseDto;

// 예제 6.21
public interface ProductService {

    ProductResponseDto getProduct(Long number);

    ProductResponseDto saveProduct(ProductDto productDto);

    ProductResponseDto changeProductName(Long number, String name) throws Exception;

    void deleteProduct(Long number) throws Exception;

}

 

위 인터페이스 DAO에서 구현한 기능을 서비스 인터페이스에서 호출해 결과값을 가져오는 작업을 수행하도록 설계

서비스에서는 클라이언트가 요청한 데이터를 적절하게 가공해서 컨트롤러에게 넘기는 역할을 한다. 이 과정에서 여러 메서드를 사용

위 예제를 보면 리턴 타입이 DTO객체인 것을 볼 수 있다. DAO 객체에서 엔티티타입을 사용하는 것을 고려하면 서비스 레이어에서 DTO 객체와 엔티티 객체를 각 레이어에서 변환해서 전달하는 역할도 수행

 

정리

 

이제 구현체

import java.time.LocalDateTime;

import Dto.ProductDto;
import Dto.ProductResponseDto;
import dao.ProductDAO;
import entity.Product;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

// 예제 6.22
@Service
public class ProductServiceImpl implements ProductService {

    private final ProductDAO productDAO;

    @Autowired
    public ProductServiceImpl(ProductDAO productDAO) {
        this.productDAO = productDAO;
    }

    // 예제 6.23
    @Override
    public ProductResponseDto getProduct(Long number) {
        Product product = productDAO.selectProduct(number);

        ProductResponseDto productResponseDto = new ProductResponseDto();
        productResponseDto.setNumber(product.getNumber());
        productResponseDto.setName(product.getName());
        productResponseDto.setPrice(product.getPrice());
        productResponseDto.setStock(product.getStock());

        return productResponseDto;
    }

    // 예제 6.24
    @Override
    public ProductResponseDto saveProduct(ProductDto productDto) {
        Product product = new Product();
        product.setName(productDto.getName());
        product.setPrice(productDto.getPrice());
        product.setStock(productDto.getStock());
        product.setCreatedAt(LocalDateTime.now());
        product.setUpdatedAt(LocalDateTime.now());

        Product savedProduct = productDAO.insertProduct(product);

        ProductResponseDto productResponseDto = new ProductResponseDto();
        productResponseDto.setNumber(savedProduct.getNumber());
        productResponseDto.setName(savedProduct.getName());
        productResponseDto.setPrice(savedProduct.getPrice());
        productResponseDto.setStock(savedProduct.getStock());

        return productResponseDto;
    }

    // 예제 6.25
    @Override
    public ProductResponseDto changeProductName(Long number, String name) throws Exception {
        Product changedProduct = productDAO.updateProductName(number, name);

        ProductResponseDto productResponseDto = new ProductResponseDto();
        productResponseDto.setNumber(changedProduct.getNumber());
        productResponseDto.setName(changedProduct.getName());
        productResponseDto.setPrice(changedProduct.getPrice());
        productResponseDto.setStock(changedProduct.getStock());

        return productResponseDto;
    }

    // 예제 6.26
    @Override
    public void deleteProduct(Long number) throws Exception {
        productDAO.deleteProduct(number);
    }
}

컨트롤러 생성

package controller;

import Dto.ChangeProductNameDto;
import Dto.ProductDto;
import Dto.ProductResponseDto;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import service.ProductService;

// 예제 6.27
@RestController
@RequestMapping("/product")
public class ProductController {
    private final ProductService productService;

    @Autowired
    public ProductController(ProductService productService) {
        this.productService = productService;
    }

    @GetMapping()
    public ResponseEntity<ProductResponseDto> getProduct(Long number) {
        ProductResponseDto productResponseDto = productService.getProduct(number);

        return ResponseEntity.status(HttpStatus.OK).body(productResponseDto);
    }

    @PostMapping()
    public ResponseEntity<ProductResponseDto> createProduct(@RequestBody ProductDto productDto) {
        ProductResponseDto productResponseDto = productService.saveProduct(productDto);

        return ResponseEntity.status(HttpStatus.OK).body(productResponseDto);
    }

    @PutMapping()
    public ResponseEntity<ProductResponseDto> changeProductName(
            @RequestBody ChangeProductNameDto changeProductNameDto) throws Exception {
        ProductResponseDto productResponseDto = productService.changeProductName(
                changeProductNameDto.getNumber(),
                changeProductNameDto.getName());

        return ResponseEntity.status(HttpStatus.OK).body(productResponseDto);

    }

    @DeleteMapping()
    public ResponseEntity<String> deleteProduct(Long number) throws Exception {
        productService.deleteProduct(number);

        return ResponseEntity.status(HttpStatus.OK).body("정상적으로 삭제되었습니다.");
    }

}

package Dto;

// 예제 6.28
public class ChangeProductNameDto {

    private Long number;

    private String name;

    public ChangeProductNameDto(Long number, String name) {
        this.number = number;
        this.name = name;
    }

    public ChangeProductNameDto() {
    }

    public Long getNumber() {
        return this.number;
    }

    public String getName() {
        return this.name;
    }

    public void setNumber(Long number) {
        this.number = number;
    }

    public void setName(String name) {
        this.name = name;
    }

}

 

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