Question

在Hibernate 5.0.1上运行Hibernate程序时遇到以下错误：

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.abhinav.hibernate.UserDetails
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:776)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1542)
at org.hibernate.engine.internal.ForeignKeys.isTransient(ForeignKeys.java:225)
at org.hibernate.event.internal.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:499)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:99)
at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:58)
at org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:778)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:751)
at org.hibernate.internal.SessionImpl.persist(SessionImpl.java:756)
at com.abhinav.hibernate.main.HibernateTest.main(HibernateTest.java:26)

以下是配置文件：

<session-factory>

    <!-- Database connection settings -->
    <property name="connection.driver_class">org.postgresql.Driver</property>
    <property name="connection.url">jdbc:postgresql://localhost:5432/hibernatedb</property>
    <property name="connection.username">postgres</property>
    <property name="connection.password">password</property>

    <!-- JDBC connection pool (use the built-in) -->
    <property name="connection.pool_size">1</property>

    <!-- SQL dialect -->
    <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>

    <!-- Disable the second-level cache  -->
    <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">true</property>

    <!-- Drop and re-create the database schema on startup -->
    <property name="hbm2ddl.auto">create</property>


    <mapping resource="com.abhinav.hibernate.UserDetails"/>

</session-factory>

主要课程：

package com.abhinav.hibernate.main;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

import com.abhinav.hibernate.UserDetails;

public class HibernateTest {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    UserDetails userDetails = new UserDetails();

    userDetails.setUserId(1);
    userDetails.setUserName("Abhinav");

    Configuration configuration = new Configuration().configure();
    StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties());     
    SessionFactory sessionFactory = configuration.buildSessionFactory(builder.build());
    Session session = sessionFactory.openSession();
    session.getTransaction();
    System.out.println("Session: "+session);

    // session.save(userDetails);
    session.persist(userDetails);

    System.out.println("Session after save: "+session+" User details: "+userDetails.getUserId()+" "+userDetails.getUserName());
session.getTransaction().commit();
}

实体类： UserDetails包含字段userId和userName。

Answer 1

有两个问题

您需要使用

<mapping class="com.abhinav.hibernate.UserDetails"/>

如果使用注释进行映射（resource用于xml映射）。

您无法使用Hibernate 4方式为Hibernate 5构建会话工厂。正确的方法：

SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();

参考详情

Hibernate 5 :- org.hibernate.MappingException: Unknown entity

运行hibernate 5.0.1程序时出现未知实体异常

1 个答案: