spring core : Dependency Injection

spring-core/basic/build.gradle

@@ -14,9 +14,19 @@ repositories {
 
 dependencies {
     implementation 'org.springframework.boot:spring-boot-starter'
+
+    compileOnly 'org.projectlombok:lombok'
+    annotationProcessor 'org.projectlombok:lombok'
+
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
 }
 
 test {
     useJUnitPlatform()
 }
+
+configurations {
+    compileOnly {
+        extendsFrom annotationProcessor
+    }
+}

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

@@ -13,9 +13,10 @@ import org.springframework.context.annotation.FilterType;
         excludeFilters = @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = Configuration.class)
 )
 public class AutoAppConfig {
-
+/*
     @Bean(name = "memoryMemberRepository") // 수동 빈, 자동 빈 이름 같을 경우 수동 빈이 우선순위를 가진다.( 최근 스프링 부트는 에러 )
     MemberRepository memberRepository() {
         return new MemoryMemberRepository();
     }
+*/
 }

spring-core/basic/src/main/java/com/example/basic/annotation/MainDiscountPolicy.java

@@ -0,0 +1,13 @@
+package com.example.basic.annotation;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+
+import java.lang.annotation.*;
+
+@Target({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER, ElementType.TYPE, ElementType.ANNOTATION_TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+@Inherited
+@Documented
+@Qualifier("mainDiscountPolicy")
+public @interface MainDiscountPolicy {
+}

spring-core/basic/src/main/java/com/example/basic/discount/FixDiscountPolicy.java

@@ -2,7 +2,11 @@ package com.example.basic.discount;
 
 import com.example.basic.member.Grade;
 import com.example.basic.member.Member;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Component;
 
+@Component
+@Qualifier("fixDiscountPolicy")
 public class FixDiscountPolicy implements DiscountPolicy {
 
     private final int discountFixAmount = 1000;

spring-core/basic/src/main/java/com/example/basic/discount/RateDiscountPolicy.java

@@ -1,10 +1,16 @@
 package com.example.basic.discount;
 
+import com.example.basic.annotation.MainDiscountPolicy;
 import com.example.basic.member.Grade;
 import com.example.basic.member.Member;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Primary;
 import org.springframework.stereotype.Component;
 
 @Component
+@MainDiscountPolicy
+//@Qualifier("mainDiscountPolicy") // @Primary 보다 우선순위가 높다.
+//@Primary
 public class RateDiscountPolicy implements DiscountPolicy {
 
     private final int discountPercent = 10;

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

@@ -1,19 +1,23 @@
 package com.example.basic.order;
 
+import com.example.basic.annotation.MainDiscountPolicy;
 import com.example.basic.discount.DiscountPolicy;
 import com.example.basic.member.Member;
 import com.example.basic.member.MemberRepository;
+import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.stereotype.Component;
 
 @Component
+//@RequiredArgsConstructor
 public class OrderServiceImpl implements OrderService {
 
     private final MemberRepository memberRepository;
     private final DiscountPolicy discountPolicy;
 
     @Autowired
-    public OrderServiceImpl(MemberRepository memberRepository, DiscountPolicy discountPolicy) {
+    public OrderServiceImpl(MemberRepository memberRepository, @MainDiscountPolicy DiscountPolicy discountPolicy) {
         this.memberRepository = memberRepository;
         this.discountPolicy = discountPolicy;
     }

spring-core/basic/src/test/java/com/example/basic/autowired/AllBeanTest.java

@@ -0,0 +1,52 @@
+package com.example.basic.autowired;
+
+import com.example.basic.AutoAppConfig;
+import com.example.basic.discount.DiscountPolicy;
+import com.example.basic.member.Grade;
+import com.example.basic.member.Member;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.Assertions.*;
+
+class AllBeanTest {
+
+    @Test
+    void findAllBean() {
+        ApplicationContext ac = new AnnotationConfigApplicationContext(AutoAppConfig.class, DiscountService.class);
+
+        DiscountService discountService = ac.getBean(DiscountService.class);
+        Member member = new Member(1L, "userA", Grade.VIP);
+        int discountPrice = discountService.discount(member, 10000, "fixDiscountPolicy");
+
+        assertThat(discountService).isInstanceOf(DiscountService.class);
+        assertThat(discountPrice).isEqualTo(1000);
+
+        int rateDiscountPrice = discountService.discount(member, 20000, "rateDiscountPolicy");
+        assertThat(rateDiscountPrice).isEqualTo(2000);
+    }
+
+    static class DiscountService {
+        private final Map<String, DiscountPolicy> policyMap;
+        private final List<DiscountPolicy> policies;
+
+        @Autowired
+        public DiscountService(Map<String, DiscountPolicy> policyMap, List<DiscountPolicy> policies) {
+            this.policyMap = policyMap;
+            this.policies = policies;
+            System.out.println("policyMap = " + policyMap);
+            System.out.println("policies = " + policies);
+        }
+
+        public int discount(Member member, int price, String discountCode) {
+            DiscountPolicy discountPolicy = policyMap.get(discountCode);
+            return discountPolicy.discount(member, price);
+        }
+    }
+}

spring-core/basic/src/test/java/com/example/basic/autowired/AutowiredTest.java

@@ -0,0 +1,36 @@
+package com.example.basic.autowired;
+
+import com.example.basic.member.Member;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.lang.Nullable;
+
+import java.util.Optional;
+
+public class AutowiredTest {
+
+    @Test
+    void autowiredOption() {
+        AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(TestBean.class);
+
+    }
+
+    static class TestBean {
+
+        @Autowired(required = false)
+        public void setNoBean1(Member noBean1) {
+            System.out.println("noBean1 = " + noBean1);
+        }
+
+        @Autowired
+        public void setNoBean2(@Nullable Member noBean2) {
+            System.out.println("noBean2 = " + noBean2);
+        }
+
+        @Autowired
+        public void setNoBean3(Optional<Member> noBean3) {
+            System.out.println("noBean3 = " + noBean3);
+        }
+    }
+}

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

@@ -0,0 +1,24 @@
+package com.example.basic.order;
+
+import com.example.basic.discount.FixDiscountPolicy;
+import com.example.basic.member.Grade;
+import com.example.basic.member.Member;
+import com.example.basic.member.MemoryMemberRepository;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.*;
+
+class OrderServiceImplTest {
+
+    @Test
+    void createOrder() {
+        MemoryMemberRepository memberRepository = new MemoryMemberRepository();
+        memberRepository.save(new Member(1L, "name", Grade.VIP));
+
+        OrderServiceImpl orderService = new OrderServiceImpl(new MemoryMemberRepository(), new FixDiscountPolicy());
+        Order order = orderService.createOrder(1L, "itemA", 10000);
+
+        assertThat(order.getDiscountPrice()).isEqualTo(1000);
+    }
+}

spring-core/basic/src/test/java/com/example/basic/scan/AutoAppConfigTest.java

@@ -1,12 +1,13 @@
 package com.example.basic.scan;
 
 import com.example.basic.AutoAppConfig;
+import com.example.basic.member.MemberRepository;
 import com.example.basic.member.MemberService;
-import org.assertj.core.api.Assertions;
+import com.example.basic.order.OrderServiceImpl;
 import org.junit.jupiter.api.Test;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
-import static org.assertj.core.api.Assertions.*;
+import static org.assertj.core.api.Assertions.assertThat;
 
 class AutoAppConfigTest {
 
@@ -16,5 +17,9 @@ class AutoAppConfigTest {
 
         MemberService memberService = ac.getBean(MemberService.class);
         assertThat(memberService).isInstanceOf(MemberService.class);
+
+        OrderServiceImpl bean = ac.getBean(OrderServiceImpl.class);
+        MemberRepository memberRepository = bean.getMemberRepository();
+        System.out.println("memberRepository = " + memberRepository);
     }
 }