jsp實作購物程序

作者：Eve Cole 更新時間：2009-07-02 17:12:58

以下是我用JSP和資料庫做的購物車的來源程式：

注意：
1.重新計費部分還沒做好，大家自己動手吧！
2、下一版將用session做。

//shop_cart.jsp

<%@ page contentType="text/html;charset=gb2312"%>
<%@ page session="true" %>
<%@ page language="java" import="java.sql.*" %>

<%

String product_type;
String action;
int product_id;
int curpage;

//商品類型
if (request.getParameter("product_type")==null){
product_type="all";
}else{
product_type=request.getParameter("product_type");
}

//頁數和商品類型參數，可以在「繼續購物」時回到上次購物的頁面
if (request.getParameter("curpage")==null){
curpage=1;
}else{
curpage=java.lang.Integer.parseInt(request.getParameter("curpage"));
}

//動作
if (request.getParameter("action")==null){
action="view";
}else{
action=request.getParameter("action");
}

//商品編號
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);

//商店編號
session.putValue("shop_id",num);
//顧客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);
}
%>

height="2">

align="center">

border="1" cellpadding="2" cellspacing="0" width="100%"

bordercolorlight="#FFB468"
bordercolordark="#FFFFFF" bgcolor="#FFB468">

href="shop_list.jsp?shop_id=<%=shop_id%>&product_type=<%=product_type%>

&curpage=<%=curpage%>">繼續購物

align="center">

border="1" cellpadding="2" cellspacing="0" width="100%"

bordercolorlight="#FFB468"
bordercolordark="#FFFFFF" bgcolor="#FFB468">

href="javascript: document.forms[0].submit()">重新計費

align="center">

border="1" cellpadding="2" cellspacing="0" width="100%"

bordercolorlight="#FFB468"
bordercolordark="#FFFFFF" bgcolor="#FFB468">

清空購物車

border="1" cellpadding="2" cellspacing="0" width="100%" bordercolorlight="#FFB468"
bordercolordark="#FFFFFF" bgcolor="#FFB468">

確認購買

bordercolorlight="#FFB468" bordercolordark="#FFFFFF" height="40">

<%
sql="select shop_product.product_id,shop_product.product_name,shop_product.product_price,

。 ct_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));
%>

<%
total=total+product_discount*cart_quantity;
total_first=total_first+product_discount*cart_quantity*product_first/100;
}
%>

商品名稱	市價	優惠價	數量	小計	定金比	定金小計	刪除
<%=product_name%>	<%=product_price%>	<%=product_discount%>	" size="3" value="<% =cart_quantity%>">	<%=product_discount*cart_quantity%>	<%=product_first + "%"%>	<%=product_firstproduct_discountcart_quantity/100.0%>	delete
總計						<%=total%>
定金總計						<%=total_first%>
結餘						<%=total-total_first%>

<%
}else{
%>

購物車為空!

<%
}
%>

資料庫操作部分

程序用到兩個表：
1 shop_cart表
cart_id int 購物車編號自動編號
cart_shop_id nvarchar 商店編號
cart_product_id nvarchar 商品編號
cart_quantity int 商品數量暫時存放購物車數據

2 shop_product表
product_id int 商品編號自動編號
shop_id nvarchar 店號
product_name nvarchar 商品名稱
product_bb nvarchar 商品介紹
product_price int 市價
product_discount int 優惠價
product_img img 圖片
product_status nvarchar 狀態
product_first int 定金比例
product_type nvanchar 商品類型存放商品資料

使用bka.java製成的javabean：bka.class可以提供資料庫的操作。

另外，需在控制面板的系統DSN中註冊bka.dsn，
從而可使JSP透過JDBC-ODBC來呼叫sql資料庫。
在頁面中呼叫javabean，基本上可採用以下方式：

<%@ page language="java" import="java.sql.*" %>

<%
String sql="select * from xxx";
ResultSet rs = RegisterBean.executeQuery(sql);
if(rs.next()) {
rs.close();
RegisterBean.closeStmt();
session.putValue("register_message","duplicate name found!");
}
%>
注意應在使用後將rs關閉。

以下是bka.java的原始程式。注意使用前需用javac加以編譯成為class檔即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;
}
}