新项目需要定义的实体类很多，每个类都需要定义主键、创建时间、最后修改时间，主键除了少数是自增其他都是雪花算法生成，为了防止代码冗余，为这些主键定义了一个公共父类BaseModel，父类域包含id、创建时间、最后修改时间这三个属性。但是继承父类后子类会报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: No identifier specified for entity: com.hhh.tenant.bean.entity.Tenant
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1794) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1109) ~[spring-context-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:869) ~[spring-context-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:405) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.7.RELEASE.jar:2.3.7.RELEASE]
at com.hhh.tenant.MicroTenantApplication.main(MicroTenantApplication.java:14) ~[classes/:na]
Caused by: org.hibernate.AnnotationException: No identifier specified for entity: com.hhh.tenant.bean.entity.Tenant
at org.hibernate.cfg.InheritanceState.determineDefaultAccessType(InheritanceState.java:266) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.cfg.InheritanceState.getElementsToProcess(InheritanceState.java:211) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:781) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.boot.model.source.internal.annotations.AnnotationMetadataSourceProcessorImpl.processEntityHierarchies(AnnotationMetadataSourceProcessorImpl.java:248) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess$1.processEntityHierarchies(MetadataBuildingProcess.java:239) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:282) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1224) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1255) ~[hibernate-core-5.4.25.Final.jar:5.4.25.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) ~[spring-orm-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:378) ~[spring-orm-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1853) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1790) ~[spring-beans-5.2.12.RELEASE.jar:5.2.12.RELEASE]
... 17 common frames omitted
大意就是没给实体类定义主键(x_x)，这是因为我们的主键是定义在父类BaseModel里的，直接继承的话idea编译器识别不到。
给父类加上@MappedSuperclass注解，问题解决。