주문과 할인 도메인 - 구현과 테스트

주문과 할인 도메인 개발

할인 정책 인터페이스

DisCountPolicy

// 할인 정책 인터페이스
public interface DiscountPolicy {

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

 

 

정액 할인 정책 구현체

FixDiscountPolicy

// 정액 할인 구현체
public class FixDiscountPolicy implements DiscountPolicy {

    private int discoutnFixAmount = 1000; // 1,000원 할인


    @Override
    public int discount(Member member, int price) {
        if (member.getGrade() == Grade.VIP) {
            return discoutnFixAmount; // VIP면 1,000원 할인
        } else {
            return 0;
        }
    }
}

 

 

주문 엔티티

Order

package inflearn.spring_core.order;

// 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;
    }


    @Override
    public String toString() {
        return "Order{" +
                "memberId=" + memberId +
                ", itemName='" + itemName + '\'' +
                ", itemPrice=" + itemPrice +
                ", discountPrice=" + discountPrice +
                '}';
//        System.out.println("order" + order); 이거 할 때 예쁘게 출력되도록 해줌.
    }

}

 

 

주문 서비스 인터페이스

OrderService

public interface OrderService {
    Order createOrder(Long memberId, String itemName, int itemPrice);
}

 

 

주문 서비스 구현체

OrderServiceImpl

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);
    }
}

 

 

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실행과 테스트

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);
    }
}

 

실행 결과

 

테스트

class OrderServiceTest {

    MemberService memberService = new MemberServiceImpl();
    OrderService orderService = new OrderServiceImpl();

    @DisplayName("주문 생성 테스트")
    @Test
    void createOrder() {
        //given
        Long memberId = 1L;
        Member member = new Member(memberId, "memberA", Grade.VIP);
        memberService.join(member);

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

        //then
        assertThat(order.getDiscountPrice()).isEqualTo(1000);
    }
}