Hibernate菜鸟求助
我用的 Hibernate3.6.10版本 mysql版本5.5

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

import com.bjsxt.hibernate.model.Student;
import com.bjsxt.hibernate.model.Teacher;


public class TeacherTest {
  public  static void main (String[] args){
  Teacher t=new Teacher();
  t.setId(1);
  t.setName("t1");
  t.setTitle("中级");
  Configuration cfg= new Configuration();
  SessionFactory sf=  cfg.configure().buildSessionFactory();
     Session session =sf.openSession();
     session.beginTransaction();
     session.save(t);
     session.getTransaction().commit();
     session.close();
     sf.close();
  
  }

}

出现问题提示：
Exception in thread "main" org.hibernate.MappingException: Unable to load class [ com.bjsxt.hibernate.Teacher] declared in Hibernate configuration <mapping/> entry
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:2369)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:2310)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2290)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:2243)
at org.hibernate.cfg.Configuration.configure(Configuration.java:2158)
at org.hibernate.cfg.Configuration.configure(Configuration.java:2137)
at TeacherTest.main(TeacherTest.java:17)
Caused by: java.lang.ClassNotFoundException: com.bjsxt.hibernate.Teacher
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.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at org.hibernate.util.ReflectHelper.classForName(ReflectHelper.java:192)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:2366)
... 6 more



我的Hibernate.cfg.xml如下
<?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>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name