请教一个问题？？

异常
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not retrieve snapshot: [Teacher#3]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:67)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.persister.entity.AbstractEntityPersister.getDatabaseSnapshot(AbstractEntityPersister.java:1048)
at org.hibernate.engine.StatefulPersistenceContext.getDatabaseSnapshot(StatefulPersistenceContext.java:246)
at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:189)
at org.hibernate.event.def.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:512)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:80)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:507)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:499)
at test.Test.main(Test.java:28)
Caused by: java.sql.SQLException: Table 'spring.teacher' doesn't exist
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2926)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1571)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1666)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2978)
at com.mysql.jdbc.Connection.execSQL(Connection.java:2902)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:933)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1027)
at org.hibernate.persister.entity.AbstractEntityPersister.getDatabaseSnapshot(AbstractEntityPersister.java:1021)
... 8 more
测试类
package test;import java.util.HashMap;import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import util.HibernateSessionFactory;public class Test { /**
 * @param args
 */
public static void main(String[] args) {
// TODO Auto-generated method stub
//1.读取Hibernate配置文件 Session session=HibernateSessionFactory.getSession();
HashMap hm=new HashMap();
hm.put("id", 3);
hm.put("name", "顾老师");
hm.put("title", "特级");
Transaction tran=session.beginTransaction();
session.saveOrUpdate("Teacher",hm);
tran.commit();
HibernateSessionFactory.closeSession();
}}
配置文件Teacher.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>
 <class entity-name="Teacher" table="teacher">
  <id column="id" name="id" type="java.lang.Integer">
   <generator class="assigned"/>
  </id>
  <property column="name" generated="never" lazy="false" name="name" type="java.lang.String"/>
  <property column="title" generated="never" lazy="false" name="title" type="java.lang.String"/>
 </class>
</hibernate-mapping>
用的是动态模型Hibernate.cfg.xml
<?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"><!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration><session-factory>
<property name="connection.username">root</property>
<property name="connection.url">
jdbc:mysql://localhost:3306/spring
</property>
<property name="dialect">
org.hibernate.dialect.MySQLDialect
</property>
<property name="myeclipse.connection.profile">MYSQL</property>
<property name="connection.password">110</property>
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
<mapping resource="po/Teacher.hbm.xml" /></session-factory></hibernate-configuration>
哪位大哥知道是怎么回事啊 谢谢啊!!!