[베이직] 스프링 컨테이너와 스프링 빈 조회

 

1. 스프링 컨테이너 생성 및 빈 조회

@Bean 을 태그 이름은 다 달라야 한다.! (요새는 디폴트로 다 다르게 하라고 알려준다고 함..)

@Configuration
public class AppConfig {

    @Bean
    public MemberService memberService() {
        return new MemberServiceImpl(memberRepository());
    }

    @Bean
    public OrderService orderService() {
        return new OrderServiceImpl(
                memberRepository(),
                discountPolicy());
    }

    @Bean
    public MemberRepository memberRepository() {
        return new MemoryMemberRepository();
    }

    @Bean
    public DiscountPolicy discountPolicy() {
        return new RateDiscountPolicy();
    }
}

테스트

->  애플리케이션만 출력한거 보면 object에 빈 객체가 들어간게 보인다. 

 

package hello.core.beanfind;

import hello.core.AppConfig;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

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("beanDefinitionName = " + beanDefinitionName + "object = " + bean);
        }
    }

    @Test
    @DisplayName("애플리케이션 빈 출력하기")
    void findApplicationBean() {
        String[] beanDefinitionNames = ac.getBeanDefinitionNames();
        for (String beanDefinitionName : beanDefinitionNames) {
            BeanDefinition beanDefinition = ac.getBeanDefinition(beanDefinitionName);

            //Role ROLE_APPLICATION: 직접 등록한 애플리케이션 빈
            //Role ROLE_INFRASTRUCTURE: 스프링이 내부에서 사용하는 빈
            if (beanDefinition.getRole() == BeanDefinition.ROLE_APPLICATION) {
                Object bean = ac.getBean(beanDefinitionName);
                System.out.println("beanDefinitionName = " + beanDefinitionName + ", object = " + bean);
            }
        }
    }
}

 

2. 스프링 빈 조회(기본 조회 및 동일한 타입, 상속관계)

2-1 ) 기본 조회

public class ApplicationContextBasicFindTest {
//이게 스프링 조회 하는 기본 방법 3가지
    AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(AppConfig.class);

    @Test
    @DisplayName("빈 이름으로 조회")
    void findBeanByName(){
        MemberService memberService =ac.getBean("memberService",MemberService.class);
        Assertions.assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
    }
    @Test
    @DisplayName("이름 없이 타입으로만 조회")
    void findBeanByType(){
        MemberService memberService =ac.getBean("memberService",MemberService.class);
        Assertions.assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
    }

    @Test
    @DisplayName("구체 타입으로 조회") //유연성이 떨어진다.
    void findBeanByName2() {
        MemberServiceImpl memberService = ac.getBean("memberService", MemberServiceImpl.class);
        Assertions.assertThat(memberService).isInstanceOf(MemberServiceImpl.class);
    }
    @Test
    @DisplayName("빈 이름으로 조회 x")
    void findBeanByNameX() {
      //  ac.getBean("xxxx",MemberService.class);
        assertThrows(NoSuchBeanDefinitionException.class,
                ()->ac.getBean("xxxx",MemberService.class));
    }


    }

2-2) 동일한 타입

package hello.core.beanfind;

import hello.core.member.MemberRepository;
import hello.core.member.MemoryMemberRepository;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Map;

public class ApplicationContextSameBeanFindTest {
    AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(SameBeanConfig.class);

    @Test
    @DisplayName("타입으로 조회시 같은 타입이 둘 이상 있으면, 중복오류가 발생한다")
    void findBeanByTypeDuplicate() {
        // ac.getBean(MemberRepository.class);
        Assertions.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);
        org.assertj.core.api.Assertions.assertThat(memberRepository).isInstanceOf(MemberRepository.class);
    }

    @Test
    @DisplayName("특정 타입을 모두 조회하기")
    void findAllBeanByType() {
        Map<String, MemberRepository> beansOdType = ac.getBeansOfType(MemberRepository.class);
        for (String key : beansOdType.keySet()) {
            System.out.println("key = " + key + "value = " + beansOdType.get(key));
        }
        System.out.println("beansOfType = " + beansOdType);
        org.assertj.core.api.Assertions.assertThat(beansOdType.size()).isEqualTo(2);
    }

    @Configuration
    static class SameBeanConfig {
        @Bean
        public MemberRepository memberRepository1() {
            return new MemoryMemberRepository();
        }

        @Bean
        public MemberRepository memberRepository2() {
            return new MemoryMemberRepository();
        }
    }
}

2-3) 상속관계

package hello.core.beanfind;

import hello.core.discount.DiscountPolicy;
import hello.core.discount.FixDiscountPolicy;
import hello.core.discount.RateDiscountPolicy;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.NoUniqueBeanDefinitionException;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Map;


public class ApplicationContextExtendsFindTest {
    AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(TestConfig.class);

    @Test
    @DisplayName("부모 타입으로 조히시, 자식이 둘 이상 있으면, 중복 오류가 발생한다")
    void findBeanByParentTypeDuplicate(){
        //DiscountPolicy bean = ac.getBean(DiscountPolicy.class);
        Assertions.assertThrows(NoUniqueBeanDefinitionException.class,
                () ->ac.getBean(DiscountPolicy.class));
    }
  @Test
    @DisplayName("부모 타입으로 조히시, 자식이 둘 이상 있으면, 빈 이름을 지정하면 된다")
    void findBeanByParentTypeBeanName(){
        DiscountPolicy rateDiscountPolicy = ac.getBean("rateDiscountPolicy",DiscountPolicy.class);
        org.assertj.core.api.Assertions.assertThat(rateDiscountPolicy).isInstanceOf(RateDiscountPolicy.class);
    }
    @Test
    @DisplayName("특정 파위 타입으로 조회")
    void findBeanBySubType(){
        DiscountPolicy bean = ac.getBean(RateDiscountPolicy.class);
        org.assertj.core.api.Assertions.assertThat(bean).isInstanceOf(RateDiscountPolicy.class);
    }

    @Test
    @DisplayName("부모타입으로 모두 조회하기")
    void findAllBeanByParentType(){
        Map<String, DiscountPolicy> beansOdType = ac.getBeansOfType(DiscountPolicy.class);
        for (String key : beansOdType.keySet()) {
            System.out.println("key = " + key + "value = " + beansOdType.get(key));
        }
        org.assertj.core.api.Assertions.assertThat(beansOdType.size()).isEqualTo(2);
    }

    @Test
    @DisplayName("부모타입으로 모두 조회하기 - Object")
    void findAllBeanByObjectType(){
        Map<String, Object> beansOdType = ac.getBeansOfType(Object.class);
        for (String key : beansOdType.keySet()) {
            System.out.println("key = " + key + "value = " + beansOdType.get(key));
        }
    }

    @Configuration
    static class TestConfig{
        @Bean
        public DiscountPolicy rateDiscountPolicy(){
            return new RateDiscountPolicy();
        }
        @Bean
        public DiscountPolicy FixDiscountPolicy(){
            return new FixDiscountPolicy();
        }
    }
}