hibernate获取SessionFactory失败 咋办？解决办法

package com.test.tree.client;import org.hibernate.cfg.Configuration;import org.hibernate.Session;import org.hibernate.SessionFactory;import com.test.pojo.Book;public class HibernateTest{    public static void main(String[] args)    {        Configuration cfg = new Configuration().configure();                SessionFactory factory = cfg.buildSessionFactory();                Session session = factory.openSession();;                session.beginTransaction();                Book book  = new Book();        book.setBook_name("轻量级JavaEE企业应用实战");        book.setBook_editor("李刚");        book.setBook_pub("电子工业出版社");        book.setBook_price((float) 99.00);                session.save(book);        session.getTransaction().commit();            }}