Hibernate学习笔记1--------一个简单的应用

工具类--------->

/**
*用单例模式读取配置文件，并返回SessionFactory和Session
*/
package com.xx.utils;

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

public final class HibernateUtil {
	private HibernateUtil(){};
	private static SessionFactory sf;
	private static Session s;
	static{
		Configuration cfg = new Configuration();
		cfg.configure();
		sf = cfg.buildSessionFactory();
	}
	public static SessionFactory getSessionFactory() {
		return sf;
	}

	public static Session getSession() {
		return sf.openSession();
	}
}

接口--------------------------->

/**
 * CURD接口
 */
package com.xx.Dao;
import com.xx.hibernate.User;
public interface UserDao {
	public void saveUser(User user);
	public User findUserById(int id);
	public User findUserByName(String name);
	public void updateUser(User user);
	public void remove(User user);

}

接口实现-------------------->

package com.itcast.Dao.impl;

import org.hibernate.Session;
import org.hibernate.Transaction;

import com.itcast.Dao.UserDao;
import com.itcast.hibernate.User;
import com.itcast.utils.HibernateUtil;

public class UserDaoImpl implements UserDao {

	public User findUserById(int id) {
		User user = null;
		Session s = null;
		try{
		    s = HibernateUtil.getSession();
		    user = (User)s.get(User.class, id);
		}finally{
			if(s != null)
				s.close();
		}
		return user;
	}

	public User findUserByName(String name) {
		User user = null;
		Session s = null;
		try{
		    s = HibernateUtil.getSession();
		    user = (User)s.createQuery("from User o where o.name =?")
		     .setParameter(0, name).uniqueResult();
		}finally{
			if(s != null)
				s.close();
		}
		return user;
	}

	public void remove(User user) {
		Session s = null;
		try{
		    s = HibernateUtil.getSession();
		    Transaction tx = s.beginTransaction();
		    s.delete(user);
		    tx.commit();
		}finally{
			if(s != null)
				s.close();
		}
	}

	public void saveUser(User user) {
		Session s = null;
		try{
		    s = HibernateUtil.getSession();
		    Transaction tx = s.beginTransaction();
		    s.save(user);
		    tx.commit();
		}finally{
			if(s != null)
				s.close();
		}
	}

	public void updateUser(User user) {
		Session s = null;
		try{
		    s = HibernateUtil.getSession();
		    Transaction tx = s.beginTransaction();
		    s.update(user);
		    tx.commit();
		}finally{
			if(s != null)
				s.close();
		}
	}

}