十一月 09, 2016 9:17:33 上午 org.hibernate.tool.hbm2ddl.SchemaExport execute
INFO: HHH000230: Schema export complete
Exception in thread "main" java.lang.NullPointerException
 at com.test.Test.add(Test.java:26)
 at com.test.Test.main(Test.java:12)

package com.test;

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

import com.entity.*;
import com.util.HibernateUnit;

public class Test {
 
 public static void main(String[] args){
  add();
  System.out.println("lallaaaaaa");
 }
 
 public static void add(){
  Grade g = new Grade("java一班","java软件开发一班");
  Student stu1 = new Student("张三丰","男");
  Student stu2 = new Student("乔峰","男");
  
  g.getStudent().add(stu1);
  g.getStudent().add(stu2);
  
  //获取会话对象
  Session session = HibernateUnit.getSession();
  Transaction tx = session.beginTransaction();
  session.save(g);
  session.save(stu1);
  session.save(stu2);
  tx.commit();
  HibernateUnit.closeSession(session);
 }
 
}