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下面是我用jsp和数据库做的购物车的源程序：
注意：
1、重新计费部分还没有做好，大家自己动手吧！
2、下一版本将用session做。
//shop_cart.jsp
<%@ page contenttype="text/html;charset=gb2312"%>
<%@ page session="true" %>
<%@ page language="java" import="java.sql.*" %>
<jsp:usebean id="bka" scope="page" class="shop.bka" />
<%
string product_type;
string action;
int product_id;
int curpage;
//商品类型
if (request.getparameter("product_type")==null){
product_type="all";
}else{
product_type=request.getparameter("product_type");
}
//页数和商品类型参数，可以在“继续购物”时返回到上次购物的页面
if (request.getparameter("curpage")==null){
curpage=1;
}else{
curpage=java.lang.integer.parseint(request.getparameter("curpage"));
}
//动作
if (request.getparameter("action")==null){
action="view";
}else{
action=request.getparameter("action");
}
//商品编号
if (request.getparameter("product_id")==null){
product_id=0;
}else{
product_id=java.lang.integer.parseint(request.getparameter("product_id"));
}
int bbb;
bbb=1;
integer num = new integer(bbb);
//商店编号
session.putvalue("shop_id",num);
//顾客username
session.putvalue("guest_name","asp2001");
string guest_name=(string)session.getvalue("guest_name");
integer shop_id=(integer)session.getvalue("shop_id");
java.lang.string sql;
java.sql.resultset rs;
if (action.compareto("add")==0) {
sql="select cart_quantity from shop_cart where cart_shop_id=" + shop_id
+ " and cart_guest_id=" + guest_name + " and cart_product_id=" + product_id ;
rs = bka.executequery(sql);
if (rs.next()){
int cart_quantity;
cart_quantity=java.lang.integer.parseint(rs.getstring("cart_quantity"))+1;
sql="update shop_cart set cart_quantity=" + cart_quantity + " where cart_shop_id="
+ shop_id + " and cart_guest_id=" + guest_name + " and cart_product_id=" + product_id ;
rs = bka.executequery(sql);}
else
{
sql="insert into shop_cart (cart_shop_id,cart_guest_id,cart_product_id,cart_quantity) values (" + shop_id + ","
+ guest_name + "," + product_id + ",1)";
rs = bka.executequery(sql);
}
}
if (action.compareto("clear")==0) {
sql="delete from shop_cart where cart_shop_id=" + shop_id + " and cart_guest_id=" + guest_name + "";
rs = bka.executequery(sql);
}
if (action.compareto("delete")==0) {
sql="delete from shop_cart where cart_shop_id=" + shop_id + " and cart_guest_id="
+ guest_name + " and cart_product_id=" + product_id ;
rs = bka.executequery(sql);
}
%>
<div align="center"><center>
<table border="0" cellpadding="0" cellspacing="0" width="610"
height="2">
<tr>
<td><form method="post"
action="shop_cart.jsp?action=update&product_type=<%=product_type%>&curp
age=<%=curpage%>">
<table border="0" cellpadding="0" cellspacing="0" width="610"
height="2">
<tr>
<td width="122" height="7"><div align="center"><center><table
border="1" cellpadding="2" cellspacing="0" width="100%" bordercolorlight="#ffb468"
bordercolordark="#ffffff" bgcolor="#ffb468">
<tr>
<td width="100%"><div
align="center"><center><p>购物车</td>
</tr>
</table>
</center></div></td>
<td width="122" height="7" style="border: medium"
align="center"><div align="center"><center><table
border="1" cellpadding="2" cellspacing="0" width="100%"
bordercolorlight="#ffb468"
bordercolordark="#ffffff" bgcolor="#ffb468">
<tr>
<td width="100%"><div align="center"><center><p><a
href="shop_list.jsp?shop_id=<%=shop_id%>&product_type=<%=product_type%>
&curpage=<%=curpage%>">继续购物</a></td>
</tr>
</table>
</center></div></td>
<td width="122" height="7" style="border: medium"
align="center"><div align="center"><center><table
border="1" cellpadding="2" cellspacing="0" width="100%"
bordercolorlight="#ffb468"
bordercolordark="#ffffff" bgcolor="#ffb468">
<tr>
<td width="100%"><div align="center"><center><p><a
href="javascript: document.forms[0].submit()">重新计费</a></td>
</tr>
</table>
</center></div></td>
<td width="122" height="7" style="border: medium"
align="center"><div align="center"><center><table
border="1" cellpadding="2" cellspacing="0" width="100%"
bordercolorlight="#ffb468"
bordercolordark="#ffffff" bgcolor="#ffb468">
<tr>
<td width="100%"><div align="center"><center><p>
<a href="shop_cart.jsp?action=clear&product_type=<%=product_type%>&curpage=<%=curpage%>">清空购物车</a></td>
</tr>
</table>
</center></div></td>
<td width="122" height="7" style="border: medium" align="center"><div align="center"><center><table
border="1" cellpadding="2" cellspacing="0" width="100%" bordercolorlight="#ffb468"
bordercolordark="#ffffff" bgcolor="#ffb468">
<tr>
<td width="100%"><div align="center"><center><p><a href="shop_order.asp">确认购买</a></td>
</tr>
</table>
</center></div></td>
</tr>
<tr align="center">
<td width="610" height="1" colspan="5"><div align="center"><center>
<table border="1" cellpadding="2" cellspacing="0" width="100%" bgcolor="#fdfee2"
bordercolorlight="#ffb468" bordercolordark="#ffffff" height="40">
<tr>
<td width="20%" height="8" align="left">商品名称</td>
<td width="10%" height="8" align="left">市场价</td>
<td width="10%" height="8" align="left">优惠价</td>
<td width="10%" height="8" align="left">数量</td>
<td width="14%" height="8" align="left">小计</td>
<td width="12%" height="8" align="left">定金比例</td>
<td width="17%" height="8" align="left">定金小计</td>
<td width="17%" height="8" align="left">删除</td>
</tr>
<%
sql="select shop_product.product_id,shop_product.product_name,shop_product.product_price,
shop_product.product_discount,shop_cart.cart_quantity,shop_product.product_first from shop_cart,shop_product where shop_cart.cart_shop_id=" + shop_id + " and shop_cart.cart_guest_id=" + guest_name + " and shop_cart.cart_product_id=shop_product.product_id";
rs = bka.executequery(sql);
int total;
int total_first;
total=0;
total_first=0;
string product_name;
int product_price;
int product_discount;
int product_first;
int cart_quantity;
if (rs.next()){
while (rs.next()) {
product_id=java.lang.integer.parseint(rs.getstring(1));
product_name=rs.getstring(2);
product_price=java.lang.integer.parseint(rs.getstring(3));
product_discount=java.lang.integer.parseint(rs.getstring(4));
cart_quantity=java.lang.integer.parseint(rs.getstring(5));
product_first=java.lang.integer.parseint(rs.getstring(6));
%>
<tr>
<td width="10%" height="1" align="left"><%=product_name%></td>
<td width="10%" height="1" align="left"><%=product_price%></td>
<td width="10%" height="1" align="left"><%=product_discount%></td>
<td width="10%" height="1" align="left"><input type="text" name="<%= "t" + product_id %>" size="3" value="<%=cart_quantity%>"></td>
<td width="14%" height="1" align="left"><%=product_discount*cart_quantity%></td>
<td width="12%" height="1" align="left"><%=product_first + "%"%></td>
<td width="17%" height="1" align="left"><%=product_first*product_discount*cart_quantity/100.0%></td>
<td width="17%" height="1"><div align="center"><center><p><a href="shop_cart.jsp?action=delete&product_id=<%=product_id%>">delete</a></td>
</tr>
<%
total=total+product_discount*cart_quantity;
total_first=total_first+product_discount*cart_quantity*product_first/100;
}
%>
<tr align="center">
<td width="72%" colspan="6" height="16"><div align="right"><p>总计</td>
<td width="36%" colspan="2" height="16"><div align="left"><%=total%></td>
</tr>
<tr align="center">
<td width="72%" colspan="6" height="16"><div align="right"><p>定金总计</td>
<td width="36%" colspan="2" height="16"><div align="left"><%=total_first%></td>
</tr>
<tr align="center">
<td width="72%" colspan="6" height="16"><div align="right"><p>结余</td>
<td width="36%" colspan="2" height="16"><div align="left"><%=total-total_first%></td>
</tr>
</table>
</center></div>
<%
}else{
%>
<p align="center">购物车为空!</p>
<%
}
%>
数据库操作部分
程序用到两个表：
1 shop_cart表
cart_id int 购物车编号 自动编号
cart_shop_id nvarchar 商店编号
cart_product_id nvarchar 商品编号
cart_quantity int 商品数量
临时存放购物车数据
2 shop_product表
product_id int 商品编号 自动编号
shop_id nvarchar 商店编号
product_name nvarchar 商品名称
product_bb nvarchar 商品介绍
product_price int 市场价
product_discount int 优惠价
product_img img 图片
product_status nvarchar 状态
product_first int 定金比例
product_type nvanchar 商品类型
存放商品资料
使用bka.java制成的javabean：bka.class可以提供对数据库的操作。
另外，需在控制面板的系统dsn中注册bka.dsn，
从而可使jsp通过jdbc-odbc来调用sql数据库。
在页面中调用javabean，基本上可采用以下方式：
<%@ page language="java" import="java.sql.*" %>
<jsp:usebean id="registerbean" scope="page" class="shop.bka" />
<%
string sql="select * from xxx";
resultset rs = registerbean.executequery(sql);
if(rs.next()) {
rs.close();
registerbean.closestmt();
session.putvalue("register_message","duplicate name found!");
}
%>
注意应在使用后将rs关闭。
以下是bka.java的源程序。注意在使用前需用javac加以编译成为class文件即javabean.
–shop/bka.java–
package shop;
import java.sql.*;
public class bka {
string sdbdriver = "sun.jdbc.odbc.jdbcodbcdriver";
string sconnstr = "jdbc:odbc:bka";
connection conn = null;
resultset rs = null;
public bka() {
try {
class.forname(sdbdriver);
}
catch(java.lang.classnotfoundexception e) {
system.err.println("bka(): " + e.getmessage());
}
}
public resultset executequery(string sql) {
rs = null;
try {
conn = drivermanager.getconnection(sconnstr,"xxx","yyy");
statement stmt = conn.createstatement();
rs = stmt.executequery(sql);
}
catch(sqlexception ex) {
system.err.println("aq.executequery: " + ex.getmessage());
}
return rs;
}
}
