Question

通过＆＃34; Hibernate简介＆＃34;关于PluralSight的教程。我有这个异常错误。完整的错误是：

Exception in thread "main" org.hibernate.MappingException: Unknown entity: com.simpleprogrammer.User
    at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:776)
    at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1451)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:100)
    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:678)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:670)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:665)
    at com.simpleprogrammer.Program.main(Program.java:15)

不确定是什么问题。我创建了User.java pojo。我创建了一个与pojo匹配的表。我创建了映射，然后将映射添加到hibernate.cfg.xml文件中。但是，仍然得到错误。任何人都可以帮我解决这个问题吗？

的hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!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 name="">
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:mysql://localhost:3306</property>
  <property name="hibernate.connection.username">root</property>
  <property name="hibernate.default_schema">protein_tracker</property>
  <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
  <mapping class="com.simpleprogrammer.User" resource="com/simpleprogrammer/User.hbm.xml"/>
 </session-factory>
</hibernate-configuration>

Program.java

public class Program {
    public static void main(String[] args) {
        System.out.println("Hello World!");
        Session session = HibernateUtilities.getSessionFactory().openSession();
        session.beginTransaction();

        User user = new User();
        user.setName("Joe");
        user.setGoal(250);
        session.save(user);

        session.getTransaction().commit();
        session.close();
        HibernateUtilities.getSessionFactory().close();
    }
}

User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated Oct 17, 2015 11:44:47 AM by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="com.simpleprogrammer.User" table="USERS">
        <id name="id" type="int">
            <column name="ID" />
            <generator class="identity" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="NAME" />
        </property>
        <property name="total" type="int">
            <column name="TOTAL" />
        </property>
        <property name="goal" type="int">
            <column name="GOAL" />
        </property>
    </class>
</hibernate-mapping>

User.java

package com.simpleprogrammer;

public class User {
    private int id;
    private String name;
    private int total;
    private int goal;

    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 int getTotal() {
        return total;
    }
    public void setTotal(int total) {
        this.total = total;
    }
    public int getGoal() {
        return goal;
    }
    public void setGoal(int goal) {
        this.goal = goal;
    }
}

HibernateUtilities.java

package com.simpleprogrammer;

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

public class HibernateUtilities {

    private static SessionFactory sessionFactory;
    private static ServiceRegistry serviceRegistry;

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

            serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        }
        catch(HibernateException exception) {
            System.out.println("Problem creating session factory!");
        }   
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

Answer 1

LinhSaysHi，我用Hibernate 5执行了你的代码，我有完全相同的错误。我用Hibernate 4执行它并且没有问题。

已经为Hibernate 4创建了Pluralsight教程。这是一个与Hibernate 5配合使用的会话工厂构建器：

public class HibernateUtilities_5 {

    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder()
                    .configure("hibernate.cfg.xml").build();
            Metadata metadata = new MetadataSources(standardRegistry).getMetadataBuilder().build();
            return metadata.getSessionFactoryBuilder().build();

        } catch (HibernateException he) {
            System.out.println("Session Factory creation failure");
            throw he;
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

Answer 2

在使用Hibernate 5.1.1进行尝试时，我也遇到了同样的错误。但是我通过用StandardServiceRegistryBuilder替换ServiceRegistry接口并使用“metadatasources”来创建会话工厂来解决它。请参阅下面的代码

func md5(string: String) -> String {
        var digest = [UInt8](count: Int(CC_MD5_DIGEST_LENGTH), repeatedValue: 0)
        if let data = string.dataUsingEncoding(NSUTF8StringEncoding) {
            CC_MD5(data.bytes, CC_LONG(data.length), &digest)
        }
        var digestHex = ""
        for index in 0..<Int(CC_MD5_DIGEST_LENGTH) {
            digestHex += String(format: "%02x", digest[index])
        }

        return digestHex
    }



func phpassHash(password: String, salt: String, iterations: Int) -> String {
        var hash = md5(salt+password)
        for _ in 0..<iterations {
            hash = md5(hash+password)
        }
        return hash;
    }

我做了这些改变，它就像一个魅力。请在代码中更改加载配置文件的方式并再次尝试。如果你仍然面临障碍，请告诉我。

Answer 3

请检查您在MySQL中创建的模式名称以及hibernate.cfg文件中指定的模式名称。这对我来说不匹配，我遇到了同样的问题。

同样修改下面的连接URL并从hibernate.cfg中删除默认架构字段。 JDBC：MySQL的：//本地主机：3306 / protein_tracker

这对我有用。

Answer 4

根据Hibernate 5

更改代码

    static
    {
        try {
            //Configuration configuration = new Configuration().configure();
            serviceRegistry = new 
            StandardServiceRegistryBuilder().configure("hibernate.cfg.xml")
                                        .build();
            Metadata metadata = new MetadataSources(serviceRegistry)
                                .getMetadataBuilder().build();
            sessionFactory = metadata.getSessionFactoryBuilder().build();   
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
    public static SessionFactory getSessionFactory() {
    return sessionFactory;
    }

给出了在user.hbm.xml中提供完整的类路径

     <class name="com.simpleprogrammer.Users" table="USERS">

在hibernate.cfg.xml中映射资源

      <mapping resource="com/simpleprogrammer/Users.hbm.xml"/>

并执行以下代码

    Session session = HibernateUtilities.getSessionFactory().openSession();

    session.beginTransaction();

    Users user = new Users();

    user.setuserName("Prince");
    user.setGoal(100);
    user.setId(101);
    user.setTotal(10);

    session.save(user);

    session.getTransaction().commit(); 
    session.close();
    HibernateUtilities.getSessionFactory().close();

Answer 5

我使用了你的例子，并且能够通过一些小的调整来实现它。

已验证User.hbm.xml位于src / main / resources / com / simpleprogrammer中。已更改为小写table="users"

然后在hibernate.cfg.xml中：

从会话工厂中删除了name=""属性。
添加了<property name="hibernate.connection.password">SomePassword</property>
添加了<property name="hibernate.hbm2ddl.auto">create</property>

Answer 6

映射有一个小问题。确保指定的路径正确。当我遇到同样的问题时，我只将hibernate.cfg.xml中的映射重新修改为

<mapping class="com.simpleprogrammer.User"/>

未添加资源之类的其他属性

Answer 7

Hibernate jars存在问题... 在这里我可以看到您正在使用Hibernate 4 ....来开发项目... 所以添加休眠4.3.5 jar应该可以工作......

如果您不使用元数据，最好使用休眠4.3罐

线程＆＃34; main＆＃34;中的例外情况org.hibernate.MappingException：未知实体

7 个答案: