스프링 핵심 기능 프로젝트 3

📌 주문과 할인 도메인 개발

할인 정책 인터페이스

정액 할인 정책 구현체

public interface DiscountPolicy {

 /**
 * @return 할인 대상 금액
 */
 int discount(Member member, int price);

}

할인 정책 인터페이스

public class FixDiscountPolicy implements DiscountPolicy {

 private int discountFixAmount = 1000; //1000원 할인
 
 @Override
 public int discount(Member member, int price) {
 
    if (member.getGrade() == Grade.VIP) 
    {
     return discountFixAmount;
    } 
    else{
        return 0;
        }
    }
}

주문 엔티티

public class Order {

    private Long memberId;
    private String itemName;
    private int itemPrice;
    private int discountPrice;

    public Order(Long memberId, String itemName, int itemPrice, int discountPrice) {
        this.memberId = memberId;
        this.itemName = itemName;
        this.itemPrice = itemPrice;
        this.discountPrice = discountPrice;
    }

    public Long getMemberId() {
        return memberId;
    }

    public void setMemberId(Long memberId) {
        this.memberId = memberId;
    }

    public String getItemName() {
        return itemName;
    }

    public void setItemName(String itemName) {
        this.itemName = itemName;
    }

    public int getItemPrice() {
        return itemPrice;
    }

    public void setItemPrice(int itemPrice) {
        this.itemPrice = itemPrice;
    }

    public int getDiscountPrice() {
        return discountPrice;
    }

    public void setDiscountPrice(int discountPrice) {
        this.discountPrice = discountPrice;
    }

    public int calculatePrice() {
        return itemPrice - discountPrice;
    }

    @Override
    public String toString() {
        return "Order{" +
                "memberId=" + memberId +
                ", itemName='" + itemName + '\'' +
                ", itemPrice=" + itemPrice +
                ", discountPrice=" + discountPrice +
                '}';
    }
}

주문 서비스 인터페이스

public interface OrderService {

    Order createOrder(Long memberId, String itemName,int itemPrice);
}

주문 서비스 구현체

//OrderService의 입장에선 할인은 난 모르겠으니 너가 던져주기만해줘 (SRP)
public class OrderServiceImpl implements  OrderService{

    private final MemberRepository memberRepository = new MemoryMemberRepository();

    private final DiscountPolicy discountPolicy = new FixDiscountPolicy();

    @Override
    public Order createOrder(Long memberId, String itemName, int itemPrice) {
        Member member = memberRepository.findById(memberId);

        int disCountPrice = discountPolicy.discount(member,itemPrice);

        return new Order(memberId,itemName,itemPrice,disCountPrice);
    }
}

주문과 할인 도메인 실행

주문과 할인 정책 실행

public class OrderApp {

    public static void main(String[] args) {
        MemberService memberService = new MemberServiceImpl();
        OrderService orderService = new OrderServiceImpl();

        Long memberId = 1L;
        Member member = new Member(memberId,"memberA", Grade.VIP);
        memberService.join(member);

        Order order = orderService.createOrder(memberId,"itemA",10000);

        System.out.println("order = " + order);

    }
}

# 👉 참조 : 인프런의 김영한님 강의 , [남궁성님의 자바의정석] , 위키백과

🌜 개인 공부 기록용 블로그입니다. 오류나 틀린 부분이 있을 경우 언제든지 댓글 혹은 메일로 지적해주시면 감사하겠습니다! 😄

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