java.lang.reflect.InvocationTargetException？？？

[k.o.b.e-24]

使用hibernate4+oracle11g学习hibernate一对多关联关系，程序运行出现异常。不知道怎么解决，请大家帮忙？
下面是hibernate配置文件：

<?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>
		<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
		<property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl</property>
		<property name="connection.username">admin</property>
		<property name="connection.password">admin</property>

		<property name="show_sql">true</property>

		<mapping resource="com/pb/hibernate/po/Grade.hbm.xml" />
		<mapping resource="com/pb/hibernate/po/Student.hbm.xml" />
	</session-factory>
</hibernate-configuration>

下面是hibernate工具类：

package com.pb.hibernate.util;

import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class HibernateUtil {
	private static SessionFactory sessionFactory;
	private static ServiceRegistry serviceRegistry;
	public static SessionFactory congigureSessionFactory() throws HibernateException {
		Configuration configuration = new Configuration().configure();
		serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
		sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		return sessionFactory;
	}
}

下面是Grade持久化类：

package com.pb.hibernate.po;

import java.util.HashSet;
import java.util.Set;

public class Grade {
	private int gid;
	private String gname;
	private String gdesc;
	private Set students = new HashSet();

	public int getGid() {
		return gid;
	}

	public void setGid(int gid) {
		this.gid = gid;
	}

	public String getGname() {
		return gname;
	}

	public void setGname(String gname) {
		this.gname = gname;
	}

	public String getGdesc() {
		return gdesc;
	}

	public void setGdesc(String gdesc) {
		this.gdesc = gdesc;
	}

	public Set getStudents() {
		return students;
	}

	public void setStudents(Set students) {
		this.students = students;
	}

}

下面是Grade映射文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
	<class name="com.pb.hibernate.po.Grade" table="GRADE" lazy="false">
		<id name="gid" type="java.lang.Integer">
			<column name="GID" />
			<generator class="assigned" />
		</id>
		<property name="gname" type="java.lang.String">
			<column name="GNAME" length="10" not-null="true" />
		</property>
		<property name="gdesc" type="java.lang.String">
			<column name="GDESC" length="50" />
		</property>
		<set name="students">
			<key column="GID" />
			<one-to-many class="com.pb.hibernate.po.Student" />
		</set>
	</class>
</hibernate-mapping>

下面是Student持久化类：

package com.pb.hibernate.po;

public class Student {
	private int sid;
	private String sanme;
	private String sex;

	public int getSid() {
		return sid;
	}

	public void setSid(int sid) {
		this.sid = sid;
	}

	public String getSanme() {
		return sanme;
	}

	public void setSanme(String sanme) {
		this.sanme = sanme;
	}

	public String getSex() {
		return sex;
	}

	public void setSex(String sex) {
		this.sex = sex;
	}

}

下面是Student映射文件：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
	<class name="com.pb.hibernate.po.Student" table="STUDENT">
		<id name="sid" type="java.lang.Integer">
			<column name="SID" />
			<generator class="assigned" />
		</id>
		<property name="sname" type="java.lang.String">
			<column name="SNAME" length="10" not-null="true" />
		</property>
		<property name="sex" type="java.lang.String">
			<column name="SEX" length="20" />
		</property>
	</class>
</hibernate-mapping>

测试类：

package com.pb.hibernate.po;

import org.hibernate.Session;
import org.hibernate.Transaction;

import com.pb.hibernate.util.HibernateUtil;

public class Test {

	public static void main(String[] args) {
		save();
	}

	public static void save() {
		Grade g = new Grade();
		g.setGid(110701);
		g.setGname("计应一班");
		g.setGdesc("计算机专业应用一班");

		Student stu1 = new Student();
		stu1.setSid(11070101);
		stu1.setSanme("张华");
		stu1.setSex("男");

		Student stu2 = new Student();
		stu2.setSid(11070125);
		stu2.setSanme("刘萍");
		stu2.setSex("女");

		g.getStudents().add(stu1);
		g.getStudents().add(stu1);

		Session session = HibernateUtil.congigureSessionFactory().openSession();
		Transaction tr = session.beginTransaction();
		session.save(g);
		session.save(stu1);
		session.save(stu2);
		tr.commit();
		session.close();
	}
}

运行异常情况：
2014-12-7 12:46:48 org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation
INFO: HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
2014-12-7 12:46:48 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
2014-12-7 12:46:48 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>
INFO: HHH000397: Using ASTQueryTranslatorFactory
Exception in thread "main" org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:185)
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:135)
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:385)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1769)
at com.pb.hibernate.util.HibernateUtil.congigureSessionFactory(HibernateUtil.java:15)
at com.pb.hibernate.po.Test.save(Test.java:33)
at com.pb.hibernate.po.Test.main(Test.java:11)
Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:138)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructDefaultTuplizer(EntityTuplizerFactory.java:188)
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:341)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:507)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:146)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:163)
... 6 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:135)
... 15 more
Caused by: org.hibernate.PropertyNotFoundException: Could not find a getter for sname in class com.pb.hibernate.po.Student
at org.hibernate.property.BasicPropertyAccessor.createGetter(BasicPropertyAccessor.java:316)
at org.hibernate.property.BasicPropertyAccessor.getGetter(BasicPropertyAccessor.java:310)
at org.hibernate.mapping.Property.getGetter(Property.java:321)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildPropertyGetter(PojoEntityTuplizer.java:436)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:200)
at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:82)
... 20 more
大家帮忙看看是哪出错了？

[悠忧虫]

Caused by: org.hibernate.PropertyNotFoundException: Could not find a getter for sname in class com.pb.hibernate.po.Student Student类中找不到sname的get方法。 配置文件中配置的是sname，但是Student类中定义的属性是sanme