중복회원예외()에서 오류 발생

[질문 템플릿]
1. 강의 내용과 관련된 질문인가요? 예
2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? 예
3. 질문 잘하기 메뉴얼을 읽어보셨나요? 예

[질문 내용]

중복 회원 예외()에서 오류가 자꾸 발생합니다.

 @Test
    public void 중복_회원_예외() throws Exception {
        //Given
        Member member1 = new Member();
        member1.setName("spring");
        Member member2 = new Member();
        member2.setName("spring");

        //When
        memberService.join(member1);
        IllegalStateException e = assertThrows(IllegalStateException.class,
                () -> memberService.join(member2));


        //Then
        assertThat(e.getMessage()).isEqualTo("이미 존재하는 회원입니다.");
    }

}

Java HotSpot(TM) 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended

java.lang.IllegalStateException: 이미 존재하는 회원입니다.

at hello.hello_spring.service.MemberService.lambda$validateDuplicateMember$0(MemberService.java:39)

at java.base/java.util.Optional.ifPresent(Optional.java:178)

at hello.hello_spring.service.MemberService.validateDuplicateMember(MemberService.java:38)

at hello.hello_spring.service.MemberService.join(MemberService.java:31)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.base/java.lang.reflect.Method.invoke(Method.java:568)

at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:359)

at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:196)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)

at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:380)

at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)

at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:728)

at hello.hello_spring.service.MemberService$$SpringCGLIB$$0.join(<generated>)

at hello.hello_spring.service.MemberServiceIntegrationTest.중복_회원_예외(MemberServiceIntegrationTest.java:45)

at java.base/java.lang.reflect.Method.invoke(Method.java:568)

at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)

if (findMembers.isEmpty()) {
    throw new IllegalStateException("이미 존재하는 회원입니다.");
}