hibernate 配置文件 和一个 id生成类BaseEntity.java 和一个hibernate工具类 HibernatUtils.java

package com;



import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import org.hibernate.cfg.Configuration;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;



import com.entity.Food;

import com.entity.Husband;

import com.entity.User;

import com.entity.Wife;

import com.entity.student.Classes;

import com.entity.student.Teacher;



public class Test1 {

	private Session s;

	private Transaction tran;

	@Before

	public void before(){

		s=HibernateUtils.getSession();

		tran=s.beginTransaction();

	}

	

	public void test(){

		

		User user=(User)s.get(User.class,7);

		//持久太

		//user.setUsername("xixixi");

		//修改后不用save直接提交也可保存

		tran.commit();

		s.clear();//使对象与session没有关系 ， 脱离持久太

		

		//把游离态的user变成持久态

		tran=s.beginTransaction();

		s.update(user);

		user.setPassword("789");

		tran.commit();

		

		//将对象变成顺时太

		tran=s.beginTransaction();

		s.delete(user);

		tran.commit();

	}

	



	public void one2one(){

		Husband h=new Husband();

		Wife w=new Wife();

		//创建两个瞬时对象

		h.setName("xiaoming");

		w.setName("baby");

		w.setHusband(h);

		s.save(w);

		s.save(h);

		

	}

	@Test

	public void one2oneQuery(){

		Husband h=(Husband)s.get(Husband.class, 2);

		System.out.println(h.getName()+"-------------"+h.getWife().getName());

	}

	

	

	

	@After 

	public void after(){

		tran.commit(); 	

		HibernateUtils.closeSession(s);

	}

	

	

hibernate.cfg.xml

 

package com.entity;



import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.GenerationType;

import javax.persistence.Id;

import javax.persistence.MappedSuperclass;

@MappedSuperclass

public class BaseEntity {

	@Id

	@GeneratedValue(strategy=GenerationType.AUTO)

	private Integer id;



	public Integer getId() {

		return id;

	}



	public void setId(Integer id) {

		this.id = id;

	}





}

 BaseEntity.java

 

package com;



import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.cfg.Configuration;



public class HibernateUtils {

	private static SessionFactory sf;

	static{

		Configuration cfg=new Configuration().configure();

		//在根目录src下括号内路径可以省略

		//Configuration cfg=new Configuration().configure("/hibernate.cfg.xml");

		//读取配置文件

		sf=cfg.buildSessionFactory();

	}

	//构造会话工厂

	

	public static Session getSession(){

		return sf.openSession();	

	}

	//得到会话

	

	public static void closeSession(Session session){

		if(session!=null){

			session.close();

			}	

	}

	//关闭会话

	

}

 hibernateutils.java

用来读取配置文件，生成会话