옵션 처리

옵션 처리

주입할 스프링 빈이 없어도 동작해야 할 때가 있다.

그런데 @Autowired 만 사용하면 required 옵션의 기본값이 true 로 되어 있어서 자동 주입 대상이 없으면 오류가 발생한다.

 

 

자동 주입 대상을 옵션으로 처리하는 방법은 다음과 같다.

 

AutowiredTest 생성

package inflearn.spring_core.autowired;

import inflearn.spring_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 org.springframework.lang.Nullable;

import java.util.Optional;

public class AutowiredTest {

    @Test
    void autowiredOption() {
        ApplicationContext ac = new AnnotationConfigApplicationContext(TestBean.class); // 이러면 스프링 빈으로 등록됨.
    }

    static class TestBean {
        @Autowired(required = false)
        public void setNoBean1(Member noBean1) { // 지금 Member는 스프링이 관리하는 빈이 아니므로, 그냥 아무거나 일부러 넣은 것.
            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);
        }

    }
}

 

noBean1 자체는 출력이 안 됨.

의존관계가 없기 때문

 

 

cf. 옵션이 기본값인 true 이면(생략도 가능)

        @Autowired(required = true)
        public void setNoBean1(Member noBean1) {
            System.out.println("noBean1 = " + noBean1);
        }

에러 나온다

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'autowiredTest.TestBean': Unsatisfied dependency expressed through method 'setNoBean1' parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'inflearn.spring_core.member.Member' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}