org.hibernate.MappingException：持久性 class 未知：对于非实体 class

Question

I have issue deploying a new version of my app in tomcat. I got an exception for class which was an entity with @OneToOne relation to another entity class. In the new version of the app, the both classes are not entities anymore and don't have relation. Is appear is tried to clean the MySQL, but it fails on this step and I try the couple of tings online and still is not working, any help will be welcomed.

Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: persistent class not known: com.mikegrep.TwitterModel.PublicMetrics
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:421)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800)
    ... 25 more
Caused by: org.hibernate.MappingException: persistent class not known: com.mikegrep.TwitterModel.PublicMetrics
    at org.hibernate.boot.internal.MetadataImpl.getIdentifierType(MetadataImpl.java:427)
    at org.hibernate.type.EntityType.getIdentifierType(EntityType.java:603)
    at org.hibernate.type.EntityType.getIdentifierOrUniqueKeyType(EntityType.java:643)
    at org.hibernate.persister.entity.AbstractPropertyMapping.initIdentifierPropertyPaths(AbstractPropertyMapping.java:396)
    at org.hibernate.persister.entity.AbstractPropertyMapping.initPropertyPaths(AbstractPropertyMapping.java:365)
    at org.hibernate.persister.entity.AbstractEntityPersister.initOrdinaryPropertyPaths(AbstractEntityPersister.java:2629)
    at org.hibernate.persister.entity.AbstractEntityPersister.initPropertyPaths(AbstractEntityPersister.java:2676)
    at org.hibernate.persister.entity.AbstractEntityPersister.postConstruct(AbstractEntityPersister.java:4344)
    at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:449)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:96)
    at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77)
    at org.hibernate.metamodel.internal.MetamodelImpl.initialize(MetamodelImpl.java:181)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:319)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:471)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1498)
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58)
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365)
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409)

Answer 1

It seems like your PublicMetrics cannot be mapped correctly. Since it is not within a OneToMany relationship anymore you have to tell Hibernate how to serialize/deserialize it, eg using a javax.persistence.AttributeConverter . Its hard to make those assumptions without seeing the actual models, though.