Hibernate结合MYSQL数据库简单教程

   package cn.com.nick.hbm;

import java.util.Date;

public class News
{
private int id;
private String title;
private String content;
private Date date;

public int getId()
{
return id;
}

public void setId(int id)
{
this.id = id;
}

public String getTitle()
{
return title;
}

public void setTitle(String title)
{
this.title = title;
}

public String getContent()
{
return content;
}

public void setContent(String content)
{
this.content = content;
}

public Date getDate()
{
return date;
}

public void setDate(Date date)
{
this.date = date;
}

}

   
     
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

    
     
PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-2.0.dtd">

     
      true
     
     

     
      
com.mysql.jdbc.Driver
      
      

     

     
      thread
     
     

     
      
jdbc:mysql://localhost:3306/test
      
      

     

     
      root
     
     

     
      123
      
     

     
      
org.hibernate.dialect.MySQLDialect
      
      

     

     
      my
     

     
     

最后创建一个测试类 Test.java 代码如下，里边有注释说明

package cn.com.nick.hbm;

import java.util.Date;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.classic.Session;

public class Test
{

private static final SessionFactory sessionFactory;

static
{
try
{
// 这里创建了SessionFactory 将hibernate.cfg.xml文件放到SRC的跟路径下
// Hibernate会自己找到
sessionFactory = new Configuration().configure()
  .buildSessionFactory();
} catch (Throwable ex)
{
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory()
{
return sessionFactory;
}

public static void main(String[] args)
{
// 实例化一个新的News对象，并填充内容
News news = new News();
news.setTitle("测试标题");
news.setContent("添加测试内容");
news.setDate(new Date());

Test t = new Test();
// 调用Test类下的存储方法,相当于执行INSERT语句
// t.Save(news);
// 调用查询方法,显示数据库的内容
t.select();
// 调用更新方法
// t.update();
// 调用删除
// t.delete();
}

/**
* 一个简单的添加数据方法
* @param news news对象，这个对象将被添加到库中
*/
public void Save(News news)
{
try
{
//获取hibernate的session
Session session = Test.getSessionFactory().getCurrentSession();
session.beginTransaction();
//这里只需要调用save方法把news对象传进去就插入成功了！
session.save(news);
session.getTransaction().commit();

} catch (HibernateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}

}

/**
* 查询方法
*/
public void select()
{
try
{
Session session = Test.getSessionFactory().getCurrentSession();
session.beginTransaction();
//注意！！！这里的 News 不是表名称！ 是对象名所以要注意大小写 
String sql=" from News";
//带条件的查询
//String sql="from News where id=1";

//用session.createQuery（）执行HQL查询语句
List
     
       l = session.createQuery(sql).list();
      
//在控制台循环输出
      
for (News n : l)
      
{
      
 System.out.println(n.getId());
      
 System.out.println(n.getTitle());
      
 System.out.println(n.getContent());
      
 System.out.println(n.getDate());
      
 System.out.println("==============");
      
}
      
session.getTransaction().commit();
     

} catch (HibernateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}

/**
* 更新方法
*/
public void update()
{
try
{
Session session = Test.getSessionFactory().getCurrentSession();
session.beginTransaction();
//定义了要装载对象的ID
Integer id = 1;
//用load方法装载一个对象进来
News n = (News) session.load(News.class, new Integer(id));
//重新设置这个对象的标题
n.setTitle("更新后标题");
//用update方法更新这个对象
session.update(n);
session.getTransaction().commit();
} catch (HibernateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public void delete()
{
try
{
Session session = Test.getSessionFactory().getCurrentSession();
session.beginTransaction();
//定义了要装载对象的ID
Integer id = 6;
//用load方法装载一个对象进来
News n = (News) session.load(News.class, new Integer(id));
//用delete方法删除这个对象
session.delete(n);
session.getTransaction().commit();
} catch (HibernateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}

}