[Spring] 조회한 빈을 선택해서 사용할때

빈을 선택해서 사용하기

앞서 조회된 Bean이 2개 일때 둘중 하나만 쓰도록 변경하였다.

만약 사용자가 선택해서 쓰고 싶다면 어떻게 구현을 해야 될까?

 

 

Map과 List를 활용해보자

package hello.core.autowired;

import hello.core.AutoAppConfig;
import hello.core.discount.DiscountPolicy;
import hello.core.member.Grade;
import hello.core.member.Member;

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.assertThat;

public class AllBeanTest {

    @Test
    void findAllBean() {
        // 둘다 등록함.
        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) {
            System.out.println(discountCode);
            DiscountPolicy discountPolicy = policyMap.get(discountCode);
            return discountPolicy.discount(member, price);
        }
    }

}

 

 

 

 

 

하나씩 뜯어가면서 살펴보자

findAllBean

    @Test
    void findAllBean() {
        // 둘다 AutoAppConfig.class와 직접 DiscountService를 빈으로 등록한다.
        ApplicationContext ac = new AnnotationConfigApplicationContext(AutoAppConfig.class, DiscountService.class);

        // 등록된 bean을 가져온다.
        DiscountService discountService = ac.getBean(DiscountService.class);
        
        // member를 입력해준다.
        Member member = new Member(1L,"UserA", Grade.VIP);
        
        // fix는 무조건 10퍼센트 할인율 이므로
        // 등급에 관계없이 1000이 나와야한다.
        int discountPrice =  discountService.discount(member, 10000, "fixDiscountPolicy");

        assertThat(discountService).isInstanceOf(DiscountService.class);
        assertThat(discountPrice).isEqualTo(1000);
        
        // rate는 고객등급이 VIP 일 경우 10퍼센트 할인 이므로 
        // 역시 2000d원이 나와야 한다.
        int rateDiscountPrice =  discountService.discount(member, 20000, "rateDiscountPolicy");
        assertThat(rateDiscountPrice).isEqualTo(2000);

    }

 

DiscountService

    static class DiscountService {
        private final Map<String, DiscountPolicy> policyMap;
        private final List<DiscountPolicy> policies;

        @Autowired
        // 여기가 중요하다. 주입을 해줄때 다음과 같은 형식으로 동작한다.
        // policyMap 으로 모든 빈을 map에 담는다.
        // policies 로 모든 빈을 리스트에 담는다.
        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);

        }


        // map에서 bean이름을 꺼내와 discountPolicy를 사용자가 선택하게 해주었다.
        public int discount(Member member, int price, String discountCode) {
            System.out.println(discountCode);
            DiscountPolicy discountPolicy = policyMap.get(discountCode);
            return discountPolicy.discount(member, price);
        }
    }