hibernate (Exception building SessionFactory: Could not instantiate dialect class)

ＴＥＳＴ类
package pojo;import org.hibernate.Session;
import pojohelp.HibernateUtil;
import org.hibernate.Query;
import java.util.List;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class test {
public static void main(String args[])
{
HibernateUtil hibernateutil=new HibernateUtil();
//
//SessionFactory d;
//d=new Configuration().configure().buildSessionFactory();
//Session session = d.openSession();
//Session session = hibernateutil.currentSession();
String hql="";
String code="03130";
hql = "from Student u where u.nameid like '" + code + "%'";
try
{
Session session = hibernateutil.currentSession();
Query query = session.createQuery(hql);
}
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
HibernateUtil.closeSession();
}
}
}
HibernateUtil　类
package pojohelp;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.apache.commons.beanutils.BeanUtils;
import java.util.*;
import java.lang.reflect.Field;
import java.lang.reflect.Method;public class HibernateUtil
{
    private static final SessionFactory sessionFactory;    static
    {
        try
        {
            sessionFactory = new Configuration().configure().
                buildSessionFactory();
        }
        catch (HibernateException ex)
        {
            throw new RuntimeException("Exception building SessionFactory: " +
                                       ex.getMessage(), ex);
        }
    }
    public static final ThreadLocal session = new ThreadLocal();    public static Session currentSession() throws HibernateException
    {
        Session s = (Session) session.get();
        // Open a new Session, if this Thread has none yet
        if (s == null)
        {
            s = sessionFactory.openSession();
            session.set(s);
        }
        return s;
    }
    public static void closeSession() throws HibernateException
    {
        Session s = (Session) session.get();
        session.set(null);
        if (s != null)
            s.close();
    }
    public static Object toVO(Object poObject)throws Exception
    {
        if(poObject==null)
            return null;
        if(poObject instanceof List)
        {
            return toVOList((List)poObject);
        }
        else if(poObject instanceof Set)
        {
            return toVOSet((Set)poObject);
        }
        else
        {
            return toSingleVO(poObject);
        }
    }
    public static List toVOList(List poList)throws Exception
    {
        if(poList==null)
            return null;
        List list=new ArrayList();
        Iterator iterator=poList.iterator();
        while(iterator.hasNext())
        {
            list.add(toSingleVO(iterator.next()));
        }
        return list;
    }
    public static Set toVOSet(Set set)throws Exception
    {
        if(set==null)
            return null;
        Set tempSet=new HashSet();
        Iterator iterator=set.iterator();
        while(iterator.hasNext())
        {
            tempSet.add(toSingleVO(iterator.next()));
        }
        return tempSet;
    }
    public static Object toSingleVO(Object po)throws Exception
    {
        if(po==null)
            return null;
        String className=getRealName(po.getClass().getName());
        Object vo=Class.forName(className).newInstance();
        clearNullNumber(vo,po);
        BeanUtils.copyProperties(vo,po);
        return vo;
    }
    private static String getRealName(String className)
    {
        int x=className.indexOf('$');
        if(x<0)
        {
            return className;
        }
        else
            return className.substring(0,x);
    }
    private static void clearNullNumber(Object vo,Object po)throws Exception
    {
        Field[] fields=vo.getClass().getDeclaredFields();
        String fieldName;
        for(int i=0;i<fields.length;i++)
        {
            fieldName=fields[i].getName();
            checkZero(fieldName,po);
        }
    }
    private static void checkZero(String fieldName,Object po)throws Exception
    {
        String getterName=getMethodGetter(fieldName);
        String setterName=getMethodSetter(fieldName);
        Method[] methods=po.getClass().getDeclaredMethods();
        Method getter=null,setter=null;
        for(int i=0;i<methods.length && (getter==null || setter==null);i++)
        {
            if(getterName.equals(methods[i].getName()))
            {
                getter=methods[i];
            }
            else if(setterName.equals(methods[i].getName()))
            {
                setter=methods[i];
            }
        }
        if(getter==null || setter==null)
            return;
        Object obj=getter.invoke(po,null);
        if(obj!=null)
            return;
        Class returnType=getter.getReturnType();
        if(returnType.equals(java.math.BigDecimal.class))
        {
            System.out.println("发现 fieldName="+fieldName+" 为BigDecimal的情况 并且值为NULL");
            Object[] args={new java.math.BigDecimal(0)};
            setter.invoke(po,args);
        }
    }
    private static String getMethodGetter(String fieldName)
    {
        char ch = fieldName.charAt(0);
        if (ch <= 'Z')
            return "get" + fieldName;
        ch = (char) (ch - 'a' + 'A');
        fieldName = ch + fieldName.substring(1, fieldName.length());
        return "get" + fieldName;
    }
    private static String getMethodSetter(String fieldName)
    {
        char ch = fieldName.charAt(0);
        if (ch <= 'Z')
            return "set" + fieldName;
        ch = (char) (ch - 'a' + 'A');
        fieldName = ch + fieldName.substring(1, fieldName.length());
        return "set" + fieldName;
    }
}