hibernate工具类

Posted 2020-11-30 zhai1997

因为hibernate的代码大部分都是固定的，为了将减少重复的代码的书写，可以将这些代码封装为一个工具类，获取hibernate的session对象。

1、工具类：

package pers.zhb.HibernateUtils;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtils {
public static SessionFactory sessionFactory;
static {//只执行一次，确保sessionFactory只创建一次，加载类的时候为静态变量分配一次内存
    Configuration configuration = new Configuration().configure();
    sessionFactory = configuration.buildSessionFactory();
}
public static Session openSession(){//获得session
    Session session=sessionFactory.openSession();
    return session;
}
public static Session getCurrentSession(){//获得与线程绑定的Session
    Session session=sessionFactory.getCurrentSession();
    return session;
}
}

2、测试类（查询学号为937221509的学生信息）：

import org.hibernate.Session;
import org.hibernate.Transaction;
import pers.zhb.domain.Student;
import pers.zhb.HibernateUtils.HibernateUtils;
public class HiberateSel {
    public static void testSel() {
        Session session = HibernateUtils.openSession();
        Transaction transaction = session.beginTransaction();
        Student student=session.get(Student.class,937221509);
        System.out.println(student);
        transaction.commit();
        session.close();
    }
    public static  void main(String []args){
        HiberateSel hinernateSel=new HiberateSel();
        hinernateSel.testSel();
    }
}