Question

我看过类似的帖子，但我仍然遇到问题。我已经处理了javax.persistence.Entity以及xml中的映射类，但我很难搞清楚这个。帮助!!!

线程中的异常＆＃34; main＆＃34; org.hibernate.MappingException：未知实体：com.gontuseries.hibernate.Student_Info 在org.hibernate.internal.SessionFactoryImpl.getEntityPersister（SessionFactoryImpl.java:776）在org.hibernate.internal.SessionImpl.getEntityPersister（SessionImpl.java:1451） at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId（AbstractSaveEventListener.java:100）...

package com.gontuseries.hibernate;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

public class Main {

    public static void main(String[] args) {

        // Write the Student_Info object into the database
        Student_Info student = new Student_Info();
        student.setName("Gontu");
        student.setRollNo(1);

        SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
        Session session = sessionFactory.openSession();
        session.beginTransaction();

        // this would save the Student_Info object into the database
        session.save(student);

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

package com.gontuseries.hibernate;

import javax.persistence.Column;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="STUDENT_INFORMATION")
public class Student_Info{
    @Id
    private int rollNo;
    @Column
    private String name;

    public int getRollNo() {
        return rollNo;
    }
    public void setRollNo(int rollNo) {
        this.rollNo = rollNo;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }


}

package com.gontuseries.hibernate;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;


public class HibernateUtil {

    private static final SessionFactory sessionFactory = buildSessionFactory();
    private static ServiceRegistry serviceRegistry;

    private static SessionFactory buildSessionFactory() {

        try {
            Configuration configuration = new Configuration();
            configuration.configure();

            serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
                    configuration.getProperties()).build();

            return configuration.buildSessionFactory(serviceRegistry);

        } catch (Throwable ex) {

            System.err.println("Failed to create sessionFactory object." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {

        return sessionFactory;
    }
}

<?xml version='1.0' encoding='utf-8'?>

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">


<hibernate-configuration>
    <session-factory>
        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/hibernateTutorials</property>
        <property name="connection.username">root</property>
        <property name="connection.password"></property>

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

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

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

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

        <!-- Drop the existing tables and create new one -->
        <property name="hbm2ddl.auto">create</property>

        <!-- Mention here all the model classes along with their package name -->
        <mapping class="com.gontuseries.hibernate.Student_Info"/>


    </session-factory>
</hibernate-configuration>

Answer 1

我有同样的问题。并且只添加

configuration.addAnnotatedClass(User.class);

HibernateUtil类中的

对我有所帮助。但我不认为这是添加类的正确方法，它应该通过添加hibernate.cfg.xml文件来工作，但它不会。

Answer 2

这对我有用（对于hibernate 5.1.0 jar）我正在关注http://www.gontu.org/hibernate-framework-tutorials/并遇到同样的错误。

import org.hibernate.SessionFactory;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

public class HibernateUtil {

// A SessionFactory is set up once for an application!
    final static StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
            .configure() // configures settings from hibernate.cfg.xml
            .build();
    private static SessionFactory sessionFactory=null;

private static SessionFactory buildSessionFactory() {

    try {
        sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
        return sessionFactory;
    }
    catch (Exception e) {
        // The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
        // so destroy it manually.
        StandardServiceRegistryBuilder.destroy( registry );
        throw new ExceptionInInitializerError(e);
    }

}

public static SessionFactory getSessionFactory() {
    if(sessionFactory==null){
        buildSessionFactory();
    }
    return sessionFactory;
}

}

org.hibernate.MappingException：未知实体：com.gontuseries.hibernate.Student_Info

2 个答案: