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我正在尝试在运行简单 Java 应用程序并使用 Hibernate 的 Postgresql 数据库中创建两个带有几条记录的简单表。我已经创建了实体Employee，并Department如http://viralpatel.net/blogs/hibernate-one-to-many-annotation-tutorial/中所述。我不使用 Maven。我的主要方法与两个实体位于同一个包中，如下所示：

@SuppressWarnings("deprecation")
public static void main(String[] args) {

    SessionFactory sf = new Configuration().configure().buildSessionFactory();
    Session session = sf.openSession();
    session.beginTransaction();

    Department department = new Department();
    department.setDepartmentName("Sales");
    session.save(department);

    Employee emp1 = new Employee("Nina", "Mayers", "111");
    Employee emp2 = new Employee("Tony", "Almeida", "222");

    emp1.setDepartment(department);
    emp2.setDepartment(department);

    session.save(emp1);
    session.save(emp2);

    session.getTransaction().commit();
    session.close();

}

我的 hibernate.cfg.xml 文件是：

<hibernate-configuration>
<session-factory>
    <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
    <property name="hibernate.connection.username">postgres</property>
    <property name="hibernate.connection.password">password</property>
    <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/testDB</property>
    <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.hbm2dll.auto">create-drop</property>
</session-factory>

运行应用程序后，出现以下错误：

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.al.hibernatetest.Department
at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:1063)
at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1433)
at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:116)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:205)
at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:190)
at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:91)
at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
at org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
at com.al.hibernatetest.Main.main(Main.java:24)

由于我不知道的原因，休眠无法识别实体？可能是什么问题呢？配置中有什么？一个丢失的罐子？会话的创建中有什么？

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1 回答 1

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<mapping class="net.viralpatel.hibernate.Department"/>
<mapping class="net.viralpatel.hibernate.Employee"

您忘记在 hibernate.cfg.xml 中复制这两行。

于 2013-04-26T14:33:06.860 回答