求解：一个hibernate报错的困惑

base.java
package cn.hibernate;

import java.util.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import cn.hibernate.domain.User;

public class Base {

/**
* @param args
*/
public static void main(String[] args) {
Configuration cfg =new Configuration();
cfg.configure();
SessionFactory sf =cfg.buildSessionFactory();

Session s=sf.openSession();
User user =new User();
user.setBirthday(new Date());
user.setName("name");
s.save(user);
s.close();
System.out.println("end");

}

}

User.java
package cn.hibernate.domain;

import java.util.Date;

public class User {
private int id;
private String name;
private Date birthday;
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 Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
}

hibernate.cfg.xml
<!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">oracle.jdbc.driver.OracleDriver</property>
<property name="hibernate.connection.url">jdbc:oracle:thin:@172.20.3.102:1521:mes</property>
<property name="hibernate.username">test</property>
<property name="hibernate.password">test</property>

<property name="dialect">org.hibernate.dialect.OracleDialect</property>
<property name="hbm2ddl.auto">create</property>
<mapping resource="cn/hibernate/domain/User.hbm.xml"/>
</session-factory>
</hibernate-configuration>

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">
<hibernate-mapping
package="cn.hibernage.domain">
<class name="User">
<id name="id">
<generator class="native"/>
</id>

<property name="name"/>
<property name="birthday"/>
</class>

</hibernate-mapping>
不知道哪里错了，他报
Exception in thread "main" org.hibernate.InvalidMappingException: Could not parse mapping document from resource cn/hibernate/domain/User.hbm.xml
at org.hibernate.cfg.Configuration.addResource(Configuration.java:588)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1606)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1574)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1553)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1527)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1447)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1433)
at cn.hibernate.Base.main(Base.java:18)
Caused by: org.hibernate.MappingException: class cn.hibernage.domain.User not found while looking for property: id
at org.hibernate.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:209)
at org.hibernate.mapping.SimpleValue.setTypeUsingReflection(SimpleValue.java:279)
at org.hibernate.cfg.HbmBinder.bindSimpleId(HbmBinder.java:401)
at org.hibernate.cfg.HbmBinder.bindRootPersistentClassCommonValues(HbmBinder.java:334)
at org.hibernate.cfg.HbmBinder.bindRootClass(HbmBinder.java:273)
at org.hibernate.cfg.HbmBinder.bindRoot(HbmBinder.java:144)
at org.hibernate.cfg.Configuration.add(Configuration.java:688)
at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:523)
at org.hibernate.cfg.Configuration.addResource(Configuration.java:585)
... 7 more
Caused by: java.lang.ClassNotFoundException: cn.hibernage.domain.User
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:169)
at org.hibernate.util.ReflectHelper.reflectedPropertyClass(ReflectHelper.java:205)
... 15 more
求指点。