菜鸟学习Hibernate——简单的增、删、改、查操作

讲述如何利用Hinbernate框架实现简单的数据库操作。

1、加入junit.jar

2、新建一个工具类HibernateUtils.Java把一些对session的公共操作封装起来

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

public class HibernateUtils {
/*
  *读取Hibernate.cfg.xml文件
*/
	private static SessionFactory factory;
	
	static {
		try {
			//读取hibernate.cfg.xml文件
			Configuration cfg = new Configuration().configure();
			
			//建立SessionFactory
			factory = cfg.buildSessionFactory();
		}catch(Exception e) {
			e.printStackTrace();
		}
	}
	/*
	  *打开Session
	*/
	
	public static Session getSession() {
		return factory.openSession();
	} 
	/*
	  *关闭Session
	*/
	
	public static void closeSession(Session session) {
		if (session != null) {
			if (session.isOpen()) {
				session.close();
			}
		}
	}
	
	public static SessionFactory getSessionFactory() {
		return factory;
	}
}

3、新建一个test类继承TestCase（Junit包里面的）然后下面就利用test类对User对象的增、删、改、查。

import java.util.Date;

import org.hibernate.Session;

import com.bjpowernode.hibernate.HibernateUtils;

import com.bjpowernode.hibernate.User;

import junit.framework.TestCase;

public class test extends TestCase {
/*
 * 增加User
 */
	public void testSave() {
		
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			User user = new User();
			user.setName("李四");
			user.setPassword("123");
			user.setCreateTime(new Date());
			user.setExpireTime(new Date());
			session.save(user);
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
	/**
	 * 删除
	 */
	public void testDel(){
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			User user=(User)session.load(User.class, "4028989545a244640145a24466300001");
			
			session.delete(user);
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
	
	/**
	 * 修改
	 */
	public void testUpdate(){
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			User user=(User)session.load(User.class, "4028989545a243ca0145a243cbf80001");
			user.setName("王五");
			session.update(user);
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
	
	/**
	 * 查询
	 */
	public void testLoad(){
		Session session = null;
		try {
			session = HibernateUtils.getSession();
			session.beginTransaction();
			
			User user=(User)session.load(User.class, "4028989545a243ca0145a243cbf80001");
			System.out.println(user.getName());
			System.out.println(user.getId());
			System.out.println(user.getPassword());
			System.out.println(user.getClass());
			System.out.println(user.getCreateTime());
			System.out.println(user.getExpireTime());
			session.getTransaction().commit();
		}catch(Exception e) {
			e.printStackTrace();
			session.getTransaction().rollback();
		}finally {
			HibernateUtils.closeSession(session);
		}
	}
}