cart.java

一个用Jsp+javaBean+sevlet写的购物车

package hello;
/* 
 * Source File Name: Cart.java
 * Description: 购物 
 * Copyright: ShenZhen szpt Copyright (c) 2005
 * @author 张霞
 */
import java.sql.*;
import hello.DBconn;

public class Cart
{
	  
	public Cart(){} 
	//-----------------------------用户验证------------------------------------------------------------------
	public String checkUser(String usa,String pwd)
	{
		String result="登录不成功";
		DBconn mdb = new DBconn();
		ResultSet rs =mdb.Querysimple("SELECT * FROM orderuser where username="+"'"+usa+"'");                 
                
		try{
		 if(rs.next()){
			String pass=rs.getString("password").trim();		
			if(pwd.equals(pass))
			{
				result="1";
			}else  result= "密码不对!"+pwd+pass;
				 
		  }else{ result="没有该用户!"; } 
		}catch(SQLException ex) {}	        
		return result;	
	}
	//---------------------------------选购商品--------------------------------------------------------------
	public void addOrderItem(String PID,String usa)
	{
		DBconn mdb = new DBconn();
		int pid=Integer.parseInt(PID);  
	    ResultSet rs=mdb.Querysimple("SELECT * FROM order_item where product_id="+pid+" and username="+"'"+usa+"'");                       
        int num; 
       try{      
		if(rs.next())//如果已经购买了此商品，则再次选购将更新表中购买数量"product_num"
		{
		 	num=rs.getInt("product_num");
			++num;
			String s="UPDATE order_item SET product_num = "+num+" where product_id="+pid+" and username="+"'"+usa+"'";    				 
   			mdb.executeUpdate(s);	 
		}else{//如果是第一次购买，则，将购买的商品及数量等信息插入order_item表
		      num=1; 		
		      String s="'"+pid+"'"+","+
                  	 "'"+num+"'"+","+
                  	 "'"+usa+"'";                   
      		  String odbcQuery="Insert into order_item (product_id,product_num,username) values("+s+")";
      		  mdb.executeInsert(odbcQuery);
		 	}
		 }catch(SQLException ex) {}
		mdb.Close();
	}
	//-----------------------------------------------------------------------------------------------
}