（hibernate4）org.hibernate.MappingException：未知实体 [英] (hibernate4) org.hibernate.MappingException: Unknown entity

问题描述

我是Java EE的新手，请帮忙！

以下代码使用了struts2 + hibernate4 + oracle11g。运行这段代码后，它给了我这个错误信息：

org.hibernate.MappingException：未知实体

UserDetails.java

  import javax.persistence.Entity; 
 import javax.persistence.Id; 
 import javax.persistence.Table; 
 
 import org.hibernate.Session; 
 import org.hibernate.SessionFactory; 
导入org.hibernate.cfg.Configuration; 
 import org.hibernate.service.ServiceRegistry; 
 import org.hibernate.service.ServiceRegistryBuilder; 
 
 @Entity 
 @Table（name =users）
 public class UserDetails {
 @Id 
 private int id; 
 private String passwd; 
 public String getPasswd（）{
 return passwd; 
} 
 public void setPasswd（String passwd）{
 this.passwd = passwd; 
} 
 public int getId（）{
 return id; 
} 
 public void setId（int id）{
 this.id = id; 
} 
 
 public void Update（）{
 SessionFactory sessionFactory; 
 ServiceRegistry serviceRegistry; 
 
配置配置=新配置（）; 
 configuration.configure（）; 
 serviceRegistry = new ServiceRegistryBuilder（）。applySettings（configuration.getProperties（））。buildServiceRegistry（）; 
 sessionFactory = configuration.buildSessionFactory（serviceRegistry）; 
 
会话会话= sessionFactory.openSession（）; 
 session.beginTransaction（）; 
 session.save（this）; 
 session.getTransaction（）。commit（）; 
 
 
 
 
 $ b  hibernate.cfg.xml  
 
 
 <？xml version ='1.0'encoding ='UTF-8'？> 
<！DOCTYPE hibernate-configuration PUBLIC 
 -  // Hibernate / Hibernate配置DTD 3.0 // EN
http://hibernate.sourceforge.net/hibernate-configuration-3.0 .dtd> 
< hibernate-configuration> 
 
< session-factory> 
 
< property name =dialect> org.hibernate.dialect.Oracle10gDialect< / property> 
< property name =connection.driver_class> oracle.jdbc.OracleDriver< / property> 
< property name =connection.url> jdbc：oracle：thin：@ 192.168.1.2：1521：orcl< / property> 
< property name =connection.username> steve< / property> 
< property name =connection.password> steve< / property> 
 
< property name =cache.provider_class> org.hibernate.cache.HashtableCacheProvider< / property> 
 
< property name =transaction.factory_class> org.hibernate.transaction.JDBCTransactionFactory< / property> 
< property name =current_session_context_class>线程< / property> 
< property name =hibernate.show_sql> true< / property> 
< property name =hbm2ddl.auto>建立< / property> 
< / session-factory> 
 
< / hibernate-configuration> 
  
表结构： 
 
 
 创建表用户（ID int主键，passwd varchar（45））; 
  
 
 
解决方案
您需要添加类：
  import javax.persistence.Entity; 
 import javax.persistence.Id; 
 import javax.persistence.Table; 
 
 import org.hibernate.Session; 
 import org.hibernate.SessionFactory; 
导入org.hibernate.cfg.Configuration; 
 import org.hibernate.service.ServiceRegistry; 
 import org.hibernate.service.ServiceRegistryBuilder; 
 
 @Entity 
 @Table（name =users）
 public class UserDetails {
 @Id 
 private int id; 
 private String passwd; 
 public String getPasswd（）{
 return passwd; 
} 
 public void setPasswd（String passwd）{
 this.passwd = passwd; 
} 
 public int getId（）{
 return id; 
} 
 public void setId（int id）{
 this.id = id; 
} 
 
 public void Update（）{
 SessionFactory sessionFactory; 
 ServiceRegistry serviceRegistry; 
 
配置配置=新配置（）; 
 configuration.addAnnotatedClass（UserDetails.class）; //<  - 在这里，将类添加到Hibernate配置
 configuration.configure（）; 
 serviceRegistry = new ServiceRegistryBuilder（）。applySettings（configuration.getProperties（））。buildServiceRegistry（）; 
 sessionFactory = configuration.buildSessionFactory（serviceRegistry）; 
 
会话会话= sessionFactory.openSession（）; 
 session.beginTransaction（）; 
 session.save（this）; 
 session.getTransaction（）。commit（）; 
 
 
 $ / code $ / pre 
 
 
你绝对不想构造一个新的Hibernate配置和SessionFactory，每次你想把一些东西保存到表中时，把所有东西从 Update 移动到某个init方法。
 
I am a newbie to Java EE, please help! 

The following code used struts2+hibernate4+oracle11g. After I run this code, it gives me this error message: 

  
org.hibernate.MappingException: Unknown entity
UserDetails.java
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

@Entity
@Table(name="users")
public class UserDetails {
    @Id
    private int id;
    private String passwd;
    public String getPasswd() {
        return passwd;
    }
    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }

    public void Update(){
        SessionFactory sessionFactory;
        ServiceRegistry serviceRegistry;

        Configuration configuration = new Configuration();
        configuration.configure();
        serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();        
        sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.save(this);
        session.getTransaction().commit();
    }
}
hibernate.cfg.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>

    <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
    <property name="connection.driver_class">oracle.jdbc.OracleDriver</property>
    <property name="connection.url">jdbc:oracle:thin:@192.168.1.2:1521:orcl</property>
    <property name="connection.username">steve</property>
    <property name="connection.password">steve</property>

    <property name="cache.provider_class">org.hibernate.cache.HashtableCacheProvider</property>

    <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
    <property name="current_session_context_class">thread</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hbm2ddl.auto">create</property>
  </session-factory>

</hibernate-configuration>
Table Structure:
Create table Users (ID int primary key, passwd varchar(45));

解决方案
You need to add the class:
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

@Entity
@Table(name="users")
public class UserDetails {
    @Id
    private int id;
    private String passwd;
    public String getPasswd() {
        return passwd;
    }
    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }

    public void Update(){
        SessionFactory sessionFactory;
        ServiceRegistry serviceRegistry;

        Configuration configuration = new Configuration();
        configuration.addAnnotatedClass(UserDetails.class); //<-- Here, adds the class to the Hibernate configuration
        configuration.configure();
        serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();        
        sessionFactory = configuration.buildSessionFactory(serviceRegistry);

        Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.save(this);
        session.getTransaction().commit();
    }
}
You definitely do not want to construct a new Hibernate Configuration and SessionFactory each time you want to save something to the table, so move the stuff from Update to an init method somewhere.

                        
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