Hibernate：无法加载在 Hibernate 配置中声明的类<mapping/>入口

Question

I am completely new in Hibernate and got such an stacktrace:

hql> from TracksEntity 
[2014-04-26 21:13:45] org.hibernate.MappingException: Unable to load class [ model.TracksEntity] declared in Hibernate configuration <mapping/> entry
[2014-04-26 21:13:45] java.lang.ClassNotFoundException: model.TracksEntity
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:259)
    at org.hibernate.internal.util.ReflectHelper.classForName(ReflectHelper.java:192)
    at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:2188)
    at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:2139)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2119)
    at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2072)
    at org.hibernate.cfg.Configuration.configure(Configuration.java:2045)
    at com.intellij.hibernate.remote.impl.RemoteConfigurationImpl.configure(RemoteConfigurationImpl.java:57)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:323)
    at sun.rmi.transport.Transport$1.run(Transport.java:178)
    at sun.rmi.transport.Transport$1.run(Transport.java:175)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.rmi.transport.Transport.serviceCall(Transport.java:174)
    at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:557)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:812)
    at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:671)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:744)

My hibernate.cfg.xml and TracksEntity.java was automatically generated by Intellij Idea:

TracksEntity.java: package model;

import javax.persistence.*;

@Entity
@Table(name = "TRACKS", schema = "APP", catalog = "")
public class TracksEntity {
    private int id;
    private String artist;
    private int duration;
    private String title;
    private String url;

    @Id
    @Column(name = "ID")
    public int getId () {
        return id;
    }

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

    @Basic
    @Column(name = "ARTIST")
    public String getArtist () {
        return artist;
    }

    public void setArtist (String artist) {
        this.artist = artist;
    }

    @Basic
    @Column(name = "DURATION")
    public int getDuration () {
        return duration;
    }

    public void setDuration (int duration) {
        this.duration = duration;
    }

    @Basic
    @Column(name = "TITLE")
    public String getTitle () {
        return title;
    }

    public void setTitle (String title) {
        this.title = title;
    }

    @Basic
    @Column(name = "URL")
    public String getUrl () {
        return url;
    }

    public void setUrl (String url) {
        this.url = url;
    }

    @Override
    public boolean equals (Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        TracksEntity that = (TracksEntity) o;

        if (duration != that.duration) return false;
        if (id != that.id) return false;
        if (artist != null ? !artist.equals(that.artist) : that.artist != null) return false;
        if (title != null ? !title.equals(that.title) : that.title != null) return false;
        if (url != null ? !url.equals(that.url) : that.url != null) return false;

        return true;
    }

    @Override
    public int hashCode () {
        int result = id;
        result = 31 * result + (artist != null ? artist.hashCode() : 0);
        result = 31 * result + duration;
        result = 31 * result + (title != null ? title.hashCode() : 0);
        result = 31 * result + (url != null ? url.hashCode() : 0);
        return result;
    }
}

hibernate.cfg.xml:

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="connection.url">jdbc:derby:/home/zimy/Documents/drbdb;create=true;create=true</property>
        <property name="connection.driver_class">org.apache.derby.jdbc.EmbeddedDriver</property>
        <mapping class="model.TracksEntity"/>
    </session-factory>
</hibernate-configuration>

What the problem is? I see that it is not found, but why?

Answer 1

听起来很傻，但我把我的实体类放在一个包中，这与我放在映射中的不一样......并且休眠当然找不到它......仅供参考......也许重新检查可以解决你的问题最好的问候.

Answer 2

write in this pattern

 <session-factory>

    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/dairy
    </property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password">root</property>
    <property name="hibernate.connection.pool_size">10</property>
    <property name="show_sql">true</property>
    <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.current_session_context_class">thread</property>

    <!-- MAPPING -->
    <!-- <mapping class="com.om.model.Test" /> -->
    <mapping class="com.om.model.RateCalculationBean" />

</session-factory>

and also no need to mention scema

Answer 3

I had a similar problem when the mapping file wouldn´t load correctly. The answer to this problem seems to be that we need to use the correct import statements in our Model classes.

Changing the import to import javax.persistence.Entity instead of using the one from hibernate package ( ie org.hibernate.annotations.Entity ), fixed the issue in my case.

This issue is a real pain , and I spent more than 1/2 day looking at all corners, when a simple import fixed the issue.

Hope this helps.

Answer 4

You can do it by two methods, 2nd one definitely works.

1. Either adding a mapping entry in hibernate.cfg.xml should make it work

<mapping class="com.sample.yourClass" />

2. In your code, After you create Configuration object, Do add class like,

 Configuration config = new Configuration(); config.addClass(com.sample.yourClass);

Answer 5

Worked for me :

Changing position of mapping tag in hibernate.cfg.xml for class which was not loading previously.

I kept that at top now.

Answer 6

i recently experienced this. I checked everything and didn't find anything that might have caused it. In desperation, i just moved the "/>" closer in the mapping and saved it. And it worked. Mysterious...

Answer 7

My mistake was a camel case problem. I had an embedded entity "IndexPK" and wrote "IndexPk" in the mapping file. I compared it ~20 times.... till I figured this out.

Answer 8

In my case, I have just redeployed project. Then problem solved!

Answer 9

To resolve this issue add maven spring-boot dependency

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
   <exclusions>
       <exclusion>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-logging</artifactId>
       </exclusion>
   </exclusions>

Answer 10

I was having the same issue, After adding this dependency it's resolved.

    <dependency>
        <groupId>javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.12.1.GA</version>
    </dependency>