AOP가 필요한 상황
@Transactional
public class MemberService {
private final MemberRepository memberRepository;
public MemberService(MemberRepository memberRepository) {
this.memberRepository = memberRepository;
}
/**
* 회원 가입
*/
public Long join(Member member) {
long start = System.currentTimeMillis();
try {
validateDuplicateMember(member); //중복 회원 검증
memberRepository.save(member);
return member.getId();
} finally {
long finish = System.currentTimeMillis();
long timeMs = finish - start;
System.out.println("join " + timeMs + "ms");
}
}
public List<Member> findMembers() {
long start = System.currentTimeMillis();
try {
return memberRepository.findAll();
} finally {
long finish = System.currentTimeMillis();
long timeMs = finish - start;
System.out.println("findMembers " + timeMs + "ms");
}
}
MemberServiceIntegrationTest
수행하면 join이 일어날 때 시간 측정AOP 적용
java/hello.hellospring
패키지 내에 aop
패키지를 만들고 TimeTraceAop
클래스 생성
@Component
로 선언@Aspect
@Component
public class TimeTraceAop {
@Around("execution(* hello.hellospring..*(..))") //패키지 하위에 다 적용
public Object execute(ProceedingJoinPoint joinPoint) throws Throwable {}
SpringConfig
에 @Bean
으로 등록(선호) @Bean
public TimeTraceAop timeTraceAop() {
return new TimeTraceAop();
}
- SpringConfig에 @Bean으로 등록하면 순환 참조 발생
TimeTraceAop
의 AOP 대상을 지정하는@Around
코드를 보시면,SpringConfig
의timeTraceAop()
메서드도 AOP로 처리하게 됩니다. 그런데 이게 바로 자기 자신인TimeTraceAop
를 생성하는 코드인 것이지요. 그래서 순환참조 문제가 발생합니다.
해결 방법
다음과 같이 AOP 대상에서 SpringConfig를 빼주면 됩니다.@Aspect public class TimeTraceAop { @Around("execution(* hello.hellospring..*(..)) && !target(hello.hellospring.SpringConfig)") //@Around("execution(* hello.hellospring..*(..))") public Object execute(ProceedingJoinPoint joinPoint) throws Throwable {...} }
package hello.hellospring.aop;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class TimeTraceAop {
@Around("execution(* hello.hellospring..*(..))") //패키지 하위에 다 적용
public Object execute(ProceedingJoinPoint joinPoint) throws Throwable {
long start = System.currentTimeMillis();
System.out.println("START: " + joinPoint.toString());
try {
return joinPoint.proceed();
} finally {
long finish = System.currentTimeMillis();
long timeMs = finish - start;
System.out.println("END: " + joinPoint.toString() + " " + timeMs + "ms");
}
}
}
joinPoint
의 메서드로 여러가지 조작MemberService
시간 측정 코드 제거하고 스프링부트 애플리케이션 실행START: execution(String hello.hellospring.controller.MemberController.list(Model))
START: execution(List hello.hellospring.service.MemberService.findMembers())
START: execution(List org.springframework.data.jpa.repository.JpaRepository.findAll())
Hibernate: select member0_.id as id1_0_, member0_.name as name2_0_ from member member0_
END: execution(List org.springframework.data.jpa.repository.JpaRepository.findAll()) 389ms
END: execution(List hello.hellospring.service.MemberService.findMembers()) 416ms
END: execution(String hello.hellospring.controller.MemberController.list(Model)) 463ms
@Around("execution( hello.hellospring..(..))") //패키지 하위에 다 적용
@Around("execution( hello.hellospring.service.(..))") : service 하위 다 적용
실제 proxy 주입되는지 확인 방법
@Controller public class MemberController { private final MemberService memberService; @Autowired public MemberController(MemberService memberService) { this.memberService = memberService; System.out.println("memberService = " + memberService.getClass()); }
결과(콘솔 출력)
memberService = class hello.hellospring.service.MemberService$$EnhancerBySpringCGLIB$$9b630e40
CGLIB: 멤버 서비스를 복제하는 기술
컨트롤러는 프록시 memberService를 주입 받습니다.
컨트롤러가 프록시 memberService를 호출하면 프록시 memberService가 실제 memberService를 호출합니다.