请问这是什么 错误啊
package com.imooc.test;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.imooc.entity.Employee;
import com.imooc.entity.Project;
import com.imooc.util.HibernateUtil;
/*
* 多对多关联关系的配置
* 同时建立了Project和Employee之间的双向多对多关联关系
* 关联关系的维护由Project方来处理
* */
public class Test {
public static void main(String[] args) {
Project project1 = new Project(1001,"项目一");
Project project2 = new Project(1002,"项目二");
Employee employee1 = new Employee(1,"慕女神");
Employee employee2 = new Employee(2,"imooc");
//参加项目一的员工有穆女神和imooc
project1.getEmployee().add(employee1);
project1.getEmployee().add(employee2);
//参加项目二的员工有穆女神
project2.getEmployee().add(employee1);
Session session = HibernateUtil.getSession();
Transaction tx = session.beginTransaction();
session.save(project1);
session.save(project2);
tx.commit();
HibernateUtil.closeSession(session);
}
}