[JPA] Caused by: java.lang.IllegalArgumentException: Not a managed type

에러메세지

Caused by: java.lang.IllegalArgumentException: Not a managed type: class com.group.libraryapp.domain.book.Book
at org.hibernate.metamodel.internal.MetamodelImpl.managedType(MetamodelImpl.java:582) ~[hibernate-core-5.6.9.Final.jar:5.6.9.Final]
at org.hibernate.metamodel.internal.MetamodelImpl.managedType(MetamodelImpl.java:85) ~[hibernate-core-5.6.9.Final.jar:5.6.9.Final]
at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.<init>(JpaMetamodelEntityInformation.java:75) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaEntityInformationSupport.getEntityInformation(JpaEntityInformationSupport.java:66) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getEntityInformation(JpaRepositoryFactory.java:232) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:181) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:164) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactory.getTargetRepository(JpaRepositoryFactory.java:75) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:324) ~[spring-data-commons-2.6.4.jar:2.6.4]
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.lambda$afterPropertiesSet$5(RepositoryFactoryBeanSupport.java:322) ~[spring-data-commons-2.6.4.jar:2.6.4]
at org.springframework.data.util.Lazy.getNullable(Lazy.java:230) ~[spring-data-commons-2.6.4.jar:2.6.4]
at org.springframework.data.util.Lazy.get(Lazy.java:114) ~[spring-data-commons-2.6.4.jar:2.6.4]
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:328) ~[spring-data-commons-2.6.4.jar:2.6.4]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:144) ~[spring-data-jpa-2.6.4.jar:2.6.4]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.20.jar:5.3.20]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.20.jar:5.3.20]
... 44 common frames omitted

 

원인

Spring에서 repository의 구현체를 만들 때, repository가 관리해야하는 Entity의 타입을 찾지 못해서 발생하는 에러

 

 

spring-data-jpa에서 entity information을 생성할 때 @Entity로 등록한 Jpa entity 목록을 통해서 ManagedType을 결정한다.

하지만 그냥 제네릭(T)로 구현 시 T(Object) 라는 entity가 없기 때문에 관리할 수 없는 타입이라고 나오게 된다.

 

 

해결방법

Entity가 정상적으로 Entity객체로 등록되었는지 확인해야 한다.

• @Entity 누락 (✔️ 여기에 해당했음)
• EntityScan이 안됨 (직접 @EntityScan으로 패키지 지정 시)
• 잘못된 클래스