스프링 컨테이너, 스프링 빈 대해 알아보려고 한다.
1) 스프링 컨테이너 생성
new AnnotationConfigApplicationContext(AppConfig.class);
AppConfig.class 구성 파일
2) 스프링 빈 등록
3) 스프링 빈 의존관계 설정
준비 : 스프링 빈을 등록한 다음에 의존관계 설정 준비
완료 : 스프링 컨테이너는 설정 정보를 참고해서 의존관계 주입
public class ApplicationContextInfoTest {
AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(AppConfig.class);
@Test
@DisplayName("모든 빈 출력하기")
void findAllBean(){
String[] beanDefinitionNames = ac.getBeanDefinitionNames();
for (String beanDefinitionName : beanDefinitionNames) {
Object bean = ac.getBean(beanDefinitionName);
System.out.println("name = " + beanDefinitionName + "object = " +bean);
}
}
@Test
@DisplayName("애플리케이션 빈 출력하기")
void findApplicationBean(){
String[] beanDefinitionNames = ac.getBeanDefinitionNames();
for (String beanDefinitionName : beanDefinitionNames) {
BeanDefinition beanDefinition = ac.getBeanDefinition(beanDefinitionName);
if(beanDefinition.getRole() == BeanDefinition.ROLE_APPLICATION){
Object bean = ac.getBean(beanDefinitionName);
System.out.println("name = " +beanDefinitionName + " object = " +bean);
}
}
}
}
public class ApplicationContextBasicFindTest {
AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(AppConfig.class);
@Test
@DisplayName("빈 이름으로 조회")
void findBeanByName(){
MemberService memberService = ac.getBean("memberService", MemberService.class);
assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
}
@Test
@DisplayName("이름 없이 타입으로만 조회")
void findBeanByType(){
MemberService memberService = ac.getBean(MemberService.class);
assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
}
@Test
@DisplayName("구체 타입으로 조회")
void findBeanByName2(){
MemberService memberService = ac.getBean("memberService",MemberServiceImpl.class);
}
@Test
@DisplayName("빈 이름 조회 X")
void findBeanByNameX(){
assertThrows(NoSuchBeanDefinitionException.class,
() -> ac.getBean("xxx", MemberService.class));
}
}
public class ApplicationContextSameBeanFindTest {
AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(SameBeanConfig.class);
@Test
@DisplayName("타입으로 조회시 같은 차입이 둘 이상 있으면, 중복 오류가 발생한다.")
void findBeanByTypeDuplicate(){
assertThrows(NoUniqueBeanDefinitionException.class, () -> ac.getBean(MemberRepository.class));
}
@Test
@DisplayName("타입으로 조회시 같은 타입이 둘 이상 있으면, 빈 이름을 지정하면 된다.")
void findBeanByName(){
MemberRepository memberRepository = ac.getBean("memberRepository1",MemberRepository.class);
assertThat(memberRepository).isInstanceOf(MemberRepository.class);
}
@Test
@DisplayName("특정 타입을 모두 조회하기")
void findAllBeanByType(){
Map<String, MemberRepository> beansOfType= ac.getBeansOfType(MemberRepository.class);
for(String key : beansOfType.keySet()){
System.out.println("key = " + key + " value = " +beansOfType.get(key));
}
System.out.println("beansOfType = " + beansOfType);
assertThat(beansOfType.size()).isEqualTo(2);
}
static class SameBeanConfig{
@Bean
public MemberRepository memberRepository1(){ return new MemoryMemberRepository();}
@Bean
public MemberRepository memberRepository2(){ return new MemoryMemberRepository();}
}
}
public class ApplicationContextExtendsFindTest {
AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(TestConfig.class);
@Test
@DisplayName("부모 타입으로 조회시, 자식이 둘 이상 있으면, 중복 오류가 발생한다.")
void findBeanByParentTypeDuplicate() {
assertThrows(NoUniqueBeanDefinitionException.class, () -> ac.getBean(DiscountPolicy.class));
}
@Test
@DisplayName("부모 타입으로 조회시, 자식이 둘 이상 있으면, 빈 이름을 지정하면 된다.")
void findBeanByParentTypeBeanName() {
DiscountPolicy rateDiscountPolicy = ac.getBean("rateDiscountPolicy", DiscountPolicy.class);
assertThat(rateDiscountPolicy).isInstanceOf(RateDiscountPolicy.class);
}
@Test
@DisplayName("특정 하위 타입으로 조회.")
void findBeanBySubType() {
RateDiscountPolicy bean = ac.getBean(RateDiscountPolicy.class);
assertThat(bean).isInstanceOf(RateDiscountPolicy.class);
}
@Test
@DisplayName("부모 타입으로 모두 조회하기.")
void findAllBeanByParentType() {
Map<String, DiscountPolicy> beansOfType = ac.getBeansOfType(DiscountPolicy.class);
assertThat(beansOfType.size()).isEqualTo(2);
for (String key : beansOfType.keySet()) {
System.out.println("key = " + key + " value = " + beansOfType.get(key));
}
}
@Test
@DisplayName("부모 타입으로 모두 조회하기. - Object")
void findAllBeanByObjectType() {
Map<String, Object> beansOfType = ac.getBeansOfType(Object.class);
for (String key : beansOfType.keySet()) {
System.out.println("key = " + key + " value = " + beansOfType.get(key));
}
}
@Configuration
static class TestConfig {
@Bean
public DiscountPolicy rateDiscountPolicy() { return new RateDiscountPolicy(); }
@Bean
public DiscountPolicy fixDiscountPolicy() { return new FixDiscountPolicy(); }
}
}
BeanFactory
ApplicationContext
ApplicationContext 부가 기능
상위 BeanFactory - ApplicationContext - AnnotationConfigApplicationContext/GenericXmlApplicationContext/ xxxApplicationContext
XML 설정
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="memberService" class="hello.core.member.MemberServiceImpl">
<constructor-arg name="memberRepository" ref="memberRepository"/>
</bean>
<bean id="memberRepository" class="hello.core.member.MemoryMemberRepository"/>
<bean id="orderService" class="hello.core.order.OrderServiceImpl">
<constructor-arg name="memberRepository" ref="memberRepository"/>
<constructor-arg name="discountPolicy" ref="discountPolicy"/>
</bean>
<bean id="discountPolicy" class="hello.core.discount.RateDiscountPolicy"/>
</beans>
public class XmlAppConfig {
@Test
void xmlAppContext(){
ApplicationContext ac = new GenericXmlApplicationContext("classpath:appConfig.xml");
MemberService memberService = ac.getBean("memberService", MemberService.class);
assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
}
참고
https://spring.io/projects/spring-framework
다양한 형식으로 스프링 지원
: BeanDefinition
BeanDefinition을 빈 설정 메타정보라 함
이 메타 정보를 기반으로 스프링 빈을 생성
- 스프링 컨테이너는 BeanDefinition(인터페이스)에만 의존
상세하게 보자면
BeanDefinition 정보
BeanDefinitionTest 생성
BeanDefinition에 대해 너무 깊게 이해하기 보다는, 스프링이 다양한 형태의 설정 정보를 BeanDefinition으로 추상화해서 사용 하는 정도만 이해