求助！第一个hibernate程序报错 org.hibernate.MappingException: Unknown entity: com.pojo.User

短命女 2022-07-12 03:22 209阅读 0赞

***求助求助***  
**对着案例看了好久- -找不到哪里不对，为什么报错了呢，**

工程目录

![这里写图片描述][SouthEast]

hibernate.cfg.xml

<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    
    <hibernate-configuration>
        <session-factory>
            
            <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
            <property name="connection.url">jdbc:mysql://localhost:3306/hibernate4</property>
            <property name="connection.username">root</property>
            <property name="connection.password">123456</property>
            <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
    
            <mapping resource="com/pojo/User.hbm.xml"/>
        </session-factory>
    </hibernate-configuration>

User.java

package com.pojo;
    
    public class User {
        private int id;
        private String name;
        private String pwd;
    
        public int getId() {
            return id;
        }
        public void setId(int id) {
            this.id = id;
        }
        public String getName() {
            return name;
        }
        public void setName(String name) {
            this.name = name;
        }
        public String getPwd() {
            return pwd;
        }
        public void setPwd(String pwd) {
            this.pwd = pwd;
        }
    }

User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
    
    <hibernate-mapping>
        <class name="com.pojo.User_po" table="user">
            <id name="id">
                <generator class="native"></generator>
            </id>
            <property name="name"/> 
            <property name="pwd"/>  
        </class>
    </hibernate-mapping>

Test.java

package com.test;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.Transaction;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.cfg.Configuration;
    import org.hibernate.service.ServiceRegistry;
    
    import com.pojo.User;
    
    public class Test {
        public static void main(String[] args) {
    
            Configuration cfg=new Configuration().configure();
    
            ServiceRegistry sr=new StandardServiceRegistryBuilder()
                                   .applySettings(cfg.getProperties())
                                   .build();
            SessionFactory sf=cfg.buildSessionFactory(sr);
    
            Session session=sf.openSession();
    
            Transaction tx=session.beginTransaction();
    
            User user=new User();
            user.setName("hibernate测试");
            user.setPwd("admin");
    
            session.save(user);
    
            tx.commit();
    
            session.close(); 
        }
    }

数据库

![这里写图片描述][SouthEast 1]

错误信息

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.pojo.User
        at org.hibernate.metamodel.internal.MetamodelImpl.entityPersister(MetamodelImpl.java:620)
        at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1627)
        at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:104)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
        at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
        at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
        at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
        at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:682)
        at org.hibernate.internal.SessionImpl.save(SessionImpl.java:674)
        at org.hibernate.internal.SessionImpl.save(SessionImpl.java:669)
        at com.test.Test.main(Test.java:36)

[SouthEast]: /images/20220711/68e60e6aeeb24705b363870ff0baf087.png
[SouthEast 1]: /images/20220711/e1e77416efa84a7fb475b4cfa4c5c8c1.png