Question

我是hibernate的新手。我正在尝试从“用户”表中获取所有用户的列表，我收到以下错误：

org.hibernate.hql.ast.QuerySyntaxException: User is not mapped [from User]

这是我写给用户的代码：

    package com.test;

import java.util.Iterator;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;


public class UserLogin extends Action {
  private static SessionFactory factory; 
    @Override
    public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
       // User user = new User();
       // user.setUserid(request.getParameter("userid"));
      //  user.setPassword(request.getParameter("password"));

  factory = new Configuration().configure().buildSessionFactory();
        SessionFactory sf = (SessionFactory) servlet.getServletContext().getAttribute(HibernatePlugin.SESSION_FACTORY_KEY);
        System.out.println("SessionFactory" +sf);
        Session session = factory.openSession();
        Transaction tx = session.beginTransaction();

           List<User> users = (List<User>) session.createQuery("from User").list();
   // List users = session.createQuery("FROM User").list(); 
        System.out.println("users" +users);
         for (Iterator iterator = users.iterator(); iterator.hasNext();){
            User user = (User)iterator.next(); 
            System.out.println("First Name: " + user.getUserid()); 
            System.out.println(" Last Name: " + user.getPassword()); 

       }

        return mapping.findForward("success");

    }

}

这是我的Hibernate配置文件

<?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="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.password">root</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hbm2ddl.auto">update</property>
    <!--<mapping resource="user.hbm.xml"/>-->

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

这是我的用户类

package com.test;

import java.io.Serializable;
import javax.persistence.Column;

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


/**
 *
 * @author bhavya.t
 */
@Entity
@Table(name = "login")
public class User implements Serializable {
    public User() {}
    public User(String userid, String password) {
      this.userid = userid;
      this.password = password;

   }
     private String userid;
    private String password;

     @Id
    @Column(name = "password")
    public String getPassword() {

        return password;
    }

    /**
     * @param password the password to set
     */
    public void setPassword(String password) {

        this.password = password;
    }

    /**
     * @return the userid
     */
        @Id
    @Column(name = "userid")
    public String getUserid() {
        return userid;
    }

    /**
     * @param userid the userid to set
     */
    public void setUserid(String userid) {
        this.userid = userid;
    }

}

这是我的插件类

package com.test;

import java.net.URL;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import org.apache.struts.action.ActionServlet;
import org.apache.struts.action.PlugIn;
import org.apache.struts.config.ModuleConfig;
import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

/**
 *
 * @author bhavya.t
 */
public class HibernatePlugin implements PlugIn{
     private String _configFilePath = "/hibernate.cfg.xml";


  public static final String SESSION_FACTORY_KEY = SessionFactory.class.getName();

  private SessionFactory _factory;

 public void destroy() {
 try{
 _factory.close();
 }catch(HibernateException e){
  System.out.println("Unable to close Hibernate Session Factory: " + e.getMessage());
 }

 }

 public void init(ActionServlet servlet,ModuleConfig config) throws ServletException {

  Configuration configuration = null;
  URL configFileURL = null;
  ServletContext context = null;

 try{
  configFileURL = 
HibernatePlugin.class.getResource(_configFilePath);
  context = servlet.getServletContext();
  configuration = (new Configuration()).configure(configFileURL);
  _factory = configuration.buildSessionFactory();
  //Set the factory into session
  context.setAttribute(SESSION_FACTORY_KEY, _factory);

 }catch(HibernateException e){
  System.out.println("Error while initializing hibernate: " + e.getMessage());
 }


 }

  public void setConfigFilePath(String configFilePath) {
  if ((configFilePath == null) || (configFilePath.trim().length() == 0)) {
  throw new IllegalArgumentException("configFilePath cannot be blank or null.");
  }

  System.out.println("Setting ' configFilePath' to '"  + configFilePath + "'...");
  _configFilePath = configFilePath;
  }

}

这是Hbm文件..

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping package="com.test">

    <class dynamic-insert="false" dynamic-update="false" mutable="true" name="User" optimistic-lock="version" polymorphism="implicit" select-before-update="false" table="login">
      <meta attribute="class-description">
         This class contains the employee detail. 
      </meta>

     <!-- <id name="id" type="int" column="id">
         <generator class="native"/>
      </id>-->
      <property name="userid" column="userid" type="string"/>
      <property name="password" column="password" type="string"/>

   </class>
</hibernate-mapping>

请帮助我任何人

Answer 1

您正在为hibernate混合注释配置和xml配置。首先，用<mapping resource="user.hbm.xml"/>替换<mapping class="com.test.User"/>（现在Hibernate只会查看您的注释并忽略映射xml文件）。其次，您将userid和password都映射为@Id。您应该为您的用户拥有自动生成的ID，或者使用他们的用户名作为ID。如果是后者，请从@Id移除getPassword()，然后重试。可能还有一些问题，所以在评论中写下您的进度和新问题（如果有的话），如果可以的话，我会帮助您。

Hibernate- QuerySyntaxException：用户未映射[来自用户]

1 个答案: