spring core : apply DIP - app config

spring-core/basic/src/main/java/com/example/basic/AppConfig.java

@@ -0,0 +1,29 @@
+package com.example.basic;
+
+import com.example.basic.discount.DiscountPolicy;
+import com.example.basic.discount.FixDiscountPolicy;
+import com.example.basic.member.MemberRepository;
+import com.example.basic.member.MemberService;
+import com.example.basic.member.MemberServiceImpl;
+import com.example.basic.member.MemoryMemberRepository;
+import com.example.basic.order.OrderService;
+import com.example.basic.order.OrderServiceImpl;
+
+public class AppConfig {
+
+    public MemberService memberService() {
+        return new MemberServiceImpl(memberRepository());
+    }
+
+    private MemberRepository memberRepository() {
+        return new MemoryMemberRepository();
+    }
+
+    public OrderService orderService() {
+        return new OrderServiceImpl(memberRepository(), discountPolicy());
+    }
+
+    private DiscountPolicy discountPolicy() {
+        return new FixDiscountPolicy();
+    }
+}

spring-core/basic/src/main/java/com/example/basic/MemberApp.java

@@ -2,12 +2,13 @@ package com.example.basic;
 
 import com.example.basic.member.Grade;
 import com.example.basic.member.Member;
-import com.example.basic.member.MemberServiceImpl;
+import com.example.basic.member.MemberService;
 
 public class MemberApp {
 
     public static void main(String[] args) {
-        MemberServiceImpl memberService = new MemberServiceImpl();
+        AppConfig appConfig = new AppConfig();
+        MemberService memberService = appConfig.memberService();
         Member member = new Member(1L, "memberA", Grade.VIP);
         memberService.join(member);
 

spring-core/basic/src/main/java/com/example/basic/OrderApp.java

@@ -3,16 +3,15 @@ package com.example.basic;
 import com.example.basic.member.Grade;
 import com.example.basic.member.Member;
 import com.example.basic.member.MemberService;
-import com.example.basic.member.MemberServiceImpl;
 import com.example.basic.order.Order;
 import com.example.basic.order.OrderService;
-import com.example.basic.order.OrderServiceImpl;
 
 public class OrderApp {
 
     public static void main(String[] args) {
-        MemberService memberService = new MemberServiceImpl();
-        OrderService orderService = new OrderServiceImpl();
+        AppConfig appConfig = new AppConfig();
+        MemberService memberService = appConfig.memberService();
+        OrderService orderService = appConfig.orderService();
 
         Long memberId = 1L;
         Member member = new Member(memberId, "memberA", Grade.VIP);

spring-core/basic/src/main/java/com/example/basic/member/MemberServiceImpl.java

@@ -2,7 +2,11 @@ package com.example.basic.member;
 
 public class MemberServiceImpl implements MemberService {
 
-    private final MemberRepository memberRepository = new MemoryMemberRepository();
+    private final MemberRepository memberRepository;
+
+    public MemberServiceImpl(MemberRepository memberRepository) {
+        this.memberRepository = memberRepository;
+    }
 
     @Override
     public void join(Member member) {

spring-core/basic/src/main/java/com/example/basic/order/OrderServiceImpl.java

@@ -1,17 +1,18 @@
 package com.example.basic.order;
 
 import com.example.basic.discount.DiscountPolicy;
-import com.example.basic.discount.FixDiscountPolicy;
-import com.example.basic.discount.RateDiscountPolicy;
 import com.example.basic.member.Member;
 import com.example.basic.member.MemberRepository;
-import com.example.basic.member.MemoryMemberRepository;
 
 public class OrderServiceImpl implements OrderService {
 
-    private final MemberRepository memberRepository = new MemoryMemberRepository();
-//    private final DiscountPolicy discountPolicy = new FixDiscountPolicy();
-    private final DiscountPolicy discountPolicy = new RateDiscountPolicy();
+    private final MemberRepository memberRepository;
+    private final DiscountPolicy discountPolicy;
+
+    public OrderServiceImpl(MemberRepository memberRepository, DiscountPolicy discountPolicy) {
+        this.memberRepository = memberRepository;
+        this.discountPolicy = discountPolicy;
+    }
 
     @Override
     public Order createOrder(Long memberId, String itemName, int itemPrice) {

spring-core/basic/src/test/java/com/example/basic/member/MemberServiceTest.java

@@ -1,13 +1,21 @@
 package com.example.basic.member;
 
+import com.example.basic.AppConfig;
 import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.*;
 
 class MemberServiceTest {
 
-    MemberService memberService = new MemberServiceImpl();
+    MemberService memberService;
+
+    @BeforeEach
+    void beforeEach() {
+        AppConfig appConfig = new AppConfig();
+        memberService = appConfig.memberService();
+    }
 
     @Test
     void join() {

spring-core/basic/src/test/java/com/example/basic/order/OrderServiceTest.java

@@ -1,18 +1,27 @@
 package com.example.basic.order;
 
+import com.example.basic.AppConfig;
 import com.example.basic.member.Grade;
 import com.example.basic.member.Member;
 import com.example.basic.member.MemberService;
 import com.example.basic.member.MemberServiceImpl;
 import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.*;
 
 class OrderServiceTest {
 
-    MemberService memberService = new MemberServiceImpl();
-    OrderService orderService = new OrderServiceImpl();
+    MemberService memberService;
+    OrderService orderService;
+
+    @BeforeEach
+    void beforeEach() {
+        AppConfig appConfig = new AppConfig();
+        memberService = appConfig.memberService();
+        orderService = appConfig.orderService();
+    }
 
     @Test
     void createOrder() {