utilcontext.java

网上购物车的JAVA代码实现版

package feng.shoppingcart.util;
import feng.shoppingcart.biz.UserBiz;
import feng.shoppingcart.dao.*;

import java.util.*;
import java.io.*;

import org.hibernate.*;

import org.hibernate.cfg.Configuration;

public class UtilContext {
	private static Properties pro=new Properties();
	private static ThreadLocal<Session> tls=new ThreadLocal<Session>();
	static{
		try{
			InputStream is=UtilContext.class.getResourceAsStream("/feng/shoppingcart/util/context.properties");
			pro.load(is);
			is.close();
		}catch(Exception e){
			e.printStackTrace();
			throw new ExceptionInInitializerError(e);
		}
	}
	public static Session getSession() throws Exception{
		Session session=tls.get();
		if(session==null){
			Configuration config=null;
			SessionFactory sf=null;
			config=new Configuration();
			config=config.configure();
			sf=config.buildSessionFactory();
			session=sf.openSession();
			tls.set(session);
		}
		return session;
	}
	public static void release(Session session){
		
		if(session!=null)	session.close();
		tls.remove();
	}
	public static UserDao getUserDao()throws Exception{
		String impl=pro.getProperty("cart_user_dao");
		UserDao userdao=(UserDao)Class.forName(impl).newInstance();
		return userdao;
	}
	public static ProductDao getProductDao()throws Exception{
		String impl=pro.getProperty("cart_product_dao");
		ProductDao productdao=(ProductDao)Class.forName(impl).newInstance();
		return productdao;
	}
	public static OrderDao getOrderDao()throws Exception{
		String impl=pro.getProperty("cart_order_dao");
		OrderDao orderdao=(OrderDao)Class.forName(impl).newInstance();
		return orderdao;
	}
	public static UserBiz getUserBiz()throws Exception{
		String impl=pro.getProperty("cart_user_biz");
		UserBiz userbiz=(UserBiz)Class.forName(impl).newInstance();
		return userbiz;
	}
}