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