我正在尝试使用hibernate创建一个小项目，但出现了错误“类型未映射[从类型o中选择o]”，我在hibernate.cfg.xml中添加了映射，但仍然出错。

Type.java：

package com.formation.gestionprojet.doa.entity;

import java.io.Serializable;

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


@Entity
@Table(name="Type")
public class Type implements Serializable {
/**
 * 
 */
private static final long serialVersionUID = 1L;

@Id
private Long id;

private String name;

private String description;

private String active;




public Type() {
    super();
    // TODO Auto-generated constructor stub
}

public Long getId() {
    return id;
}

public void setId(Long id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getActive() {
    return active;
}

public void setActive(String active) {
    this.active = active;
}

}

hibernate.org.xml：

<?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 setting -->

<property name ="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/gestion_projet?createDatabaseIfNotExist=true</property>
<property name="connection.username">root</property>
<property name= "connection.password">root</property>

<!-- 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>

<!-- Drope and re-create the database -->
<property name="hbm2ddl.auto">update</property>

<!-- mapping -->


<mapping class= "com.formation.gestionprojet.doa.entity.Type"/>


</session-factory>

</hibernate-configuration>

hibernateUtil.java：

package com.formation.gestionprojet.utils;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

@SuppressWarnings("deprecation")
public class HibernateUtil
{
    private static SessionFactory sessionFactory;
    private static ServiceRegistry serviceRegistry;

    static
    {
        try
        {

            Configuration configuration = new Configuration();
            configuration.configure("config/hibernate.cfg.xml");

            serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        }
        catch (HibernateException ex)
        {
            System.err.println("Error creating Session: " + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory()
    {
        return sessionFactory;
    }



    public static Session openSession()
    {
        return sessionFactory.openSession();
    }


    public static Session getCurrentSession()
    {
        return sessionFactory.getCurrentSession();
    }


    public static void close(){
        if(sessionFactory!=null){
            sessionFactory.close();
        }

    }


}

测试Java

package com.formation.gestionprojet.utils;

import org.hibernate.Session;



public class Test {

    static Session session = HibernateUtil.openSession();

    public static void main(String[] args) {

        session.createQuery("select o from Type o").list();



    }

}