[SpringBoot]스프링부트 쇼핑몰 프로젝트 with JPA(장바구니)

CartItemDto

package com.shop.shop.dto;

import lombok.Getter;
import lombok.Setter;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;

@Getter
@Setter
public class CartItemDto {

    @NotNull(message = "상품 아이디는 필수 입력 값 입니다.")
    private  Long itemId;

    @Min(value = 1, message = "최소 1개이상 담아주세요")
    private  int count;
}

Cart

  public static Cart createCart(Member member){
        Cart cart = new Cart();
        cart.setMember(member);
        return cart;
    }

CartItem

   public static CartItem createCartItem (Cart cart, Item item, int count){
        CartItem cartItem = new CartItem();
        cartItem.setCart(cart);
        cartItem.setItem(item);
        cartItem.setCount(count);
        return cartItem;
    }

    public void  addCount(int count){
        this.count += count;
    }

CartRepository

package com.shop.shop.repository;

import com.shop.shop.entity.Cart;
import org.springframework.data.jpa.repository.JpaRepository;

public interface CartRepository extends JpaRepository<Cart, Long> {

    Cart findByMemberId(Long memberId);


}

CartItemRepository

package com.shop.shop.repository;

import com.shop.shop.entity.CartItem;
import org.springframework.data.jpa.repository.JpaRepository;

public interface CartItemRepository extends JpaRepository<CartItem, Long> {
    CartItem findByCartIdAndItemId(Long cartId, Long itemId);
}

CartService

package com.shop.shop.service;


import com.shop.shop.dto.CartItemDto;
import com.shop.shop.entity.Cart;
import com.shop.shop.entity.CartItem;
import com.shop.shop.entity.Item;
import com.shop.shop.entity.Member;
import com.shop.shop.repository.CartItemRepository;
import com.shop.shop.repository.CartRepository;
import com.shop.shop.repository.ItemRepository;
import com.shop.shop.repository.MemberRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityNotFoundException;

@Service
@RequiredArgsConstructor
@Transactional
public class CartService {

    private final ItemRepository itemRepository;
    private final MemberRepository memberRepository;
    private final CartRepository cartRepository;
    private final CartItemRepository cartItemRepository;

    public Long addCart(CartItemDto cartItemDto,String email){
        Item item = itemRepository.findById(cartItemDto.getItemId())
                .orElseThrow(EntityNotFoundException::new);
        Member member = memberRepository.findByEmail(email);

        Cart cart = cartRepository.findByMemberId(member.getId());
        if (cart == null){
            cart = Cart.createCart(member);
            cartRepository.save(cart);
        }

        CartItem savedCartItem =
                cartItemRepository.findByCartIdAndItemId(cart.getId(),item.getId());

        if (savedCartItem != null){ //장바구니에 기존 상품이 있을 경우
            savedCartItem.addCount(cartItemDto.getCount());
            return  savedCartItem.getId();
        }else {
            CartItem cartItem= CartItem.createCartItem(cart, item, cartItemDto.getCount());
            cartItemRepository.save(cartItem);
            return  cartItem.getId();
        }
    }
}

CartController

package com.shop.shop.controller;


import com.shop.shop.dto.CartItemDto;
import com.shop.shop.service.CartService;
import lombok.RequiredArgsConstructor;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.validation.Valid;
import java.security.Principal;
import java.util.List;

@Controller
@RequiredArgsConstructor
public class CartController {

    private  final CartService cartService;

    @PostMapping(value = "/cart")
    public @ResponseBody ResponseEntity order(@RequestBody @Valid CartItemDto cartItemDto,
                                              BindingResult bindingResult, Principal principal) {

        if (bindingResult.hasErrors()) {
            StringBuilder sb = new StringBuilder();
            List<FieldError> fieldErrors = bindingResult.getFieldErrors();
            for (FieldError fieldError : fieldErrors) {
                sb.append(fieldError.getDefaultMessage());
            }
            return new ResponseEntity<String>(sb.toString(), HttpStatus.BAD_REQUEST);
        }

        String email = principal.getName();
        Long cartItemId;

        try {
            cartItemId = cartService.addCart(cartItemDto,email);
        }catch (Exception e){
            return  new ResponseEntity<String>(e.getMessage(),HttpStatus.BAD_REQUEST);
        }
        return  new ResponseEntity<Long>(cartItemId, HttpStatus.OK);
    }



}

itemDtl.html 추가-> 뷰 출력 결과

CartDetailDto

package com.shop.shop.dto;


import lombok.Getter;
import lombok.Setter;

@Setter
@Getter
public class CartDetailDto {

    //hiden값으로 들어가짐 꼭 필요
    private  Long cartItemId;

    private  String itemNm;

    private  int price;

    private  int count;

    private  String imgUrl;

    public CartDetailDto(Long cartItemId, String itemNm, int price, int count, String imgUrl) {
        this.cartItemId = cartItemId;
        this.itemNm = itemNm;
        this.price = price;
        this.count = count;
        this.imgUrl = imgUrl;
    }
}

CartItemRepository

package com.shop.shop.repository;

import com.shop.shop.dto.CartDetailDto;
import com.shop.shop.entity.CartItem;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;

import java.util.List;

public interface CartItemRepository extends JpaRepository<CartItem, Long> {
    CartItem findByCartIdAndItemId(Long cartId, Long itemId);

    @Query("select new com.shop.shop.dto.CartDetailDto(ci.id, i.itemNm, i.price, ci.count, im.imgUrl) " +
            "from  CartItem  ci, ItemImg  im " +
            "join ci.item i " +
            "where  ci.cart.id = :cartId " +
            "and im.item.id = ci.item.id " +
            "and  im.repimgYn = 'Y' " +
            "order by  ci.regTime desc"
    )
    List<CartDetailDto> findCartDetailDtoList(Long cartId);
}

CartDetailDto 생성자를 이용하여 DTO를 반환할 때 "new com.shop.dto.CartDetailDto"처럼 new 키워드와 해당 Dto의 패키지, 클래스명을 적어줍니다. 또한 생성자의 파라미터 순서는 DTO 클래스에 명시한 순으로 넣어주어야 합니다.

CartService

   @Transactional(readOnly = true)
    public List<CartDetailDto> getCartList(String email){

        List<CartDetailDto> cartDetailDtoList = new ArrayList<>();

        Member member = memberRepository.findByEmail(email);
        Cart cart = cartRepository.findByMemberId(member.getId());
        if (cart == null){
            return cartDetailDtoList;
        }

        cartDetailDtoList =
                cartItemRepository.findCartDetailDtoList(cart.getId());

        return  cartDetailDtoList;
    }

CartController

  @GetMapping(value = "/cart")
    public String orderHist(Principal principal, Model model) {
        List<CartDetailDto> cartDetailist =
                cartService.getCartList(principal.getName());
        model.addAttribute("cartItems",cartDetailist);
        return "cart/cartList";
    }