0109.htm

JspServlet教程专栏 对javaservlet讲述的非常详细

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;100%&quot;&gt;&lt;div align=&quot;center&quot;&gt;&lt;center&gt;&lt;p&gt;&lt;a href=&quot;shop_cart.jsp?action=clear&amp;product_type=&lt;%=product_type%&gt;&amp;curpage=&lt;%=curpage%&gt;&quot;&gt;清空购物车&lt;/a&gt;&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/table&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/center&gt;&lt;/div&gt;&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;122&quot; height=&quot;7&quot; style=&quot;border: medium&quot; align=&quot;center&quot;&gt;&lt;div align=&quot;center&quot;&gt;&lt;center&gt;&lt;table<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;border=&quot;1&quot; cellpadding=&quot;2&quot; cellspacing=&quot;0&quot; width=&quot;100%&quot; bordercolorlight=&quot;#FFB468&quot;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;bordercolordark=&quot;#FFFFFF&quot; bgcolor=&quot;#FFB468&quot;&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;100%&quot;&gt;&lt;div align=&quot;center&quot;&gt;&lt;center&gt;&lt;p&gt;&lt;a href=&quot;shop_order.asp&quot;&gt;确认购买&lt;/a&gt;&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/table&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/center&gt;&lt;/div&gt;&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;tr align=&quot;center&quot;&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;610&quot; height=&quot;1&quot; colspan=&quot;5&quot;&gt;&lt;div align=&quot;center&quot;&gt;&lt;center&gt;<br>
&lt;table border=&quot;1&quot; cellpadding=&quot;2&quot; cellspacing=&quot;0&quot; width=&quot;100%&quot; bgcolor=&quot;#FDFEE2&quot; bordercolorlight=&quot;#FFB468&quot; bordercolordark=&quot;#FFFFFF&quot; height=&quot;40&quot;&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;20%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;商品名称&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;10%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;市场价&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;10%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;优惠价&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;10%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;数量&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;14%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;小计&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;12%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;定金比例&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;17%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;定金小计&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;td width=&quot;17%&quot; height=&quot;8&quot; align=&quot;left&quot;&gt;删除&lt;/td&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/tr&gt;<br>
&lt;%<br>
sql=&quot;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=&quot; + shop_id + &quot; and shop_cart.cart_guest_id='&quot; + guest_name + &quot;' and shop_cart.cart_product_id=shop_product.product_id&quot;;<br>
rs = bka.executeQuery(sql);<br>
int total;<br>
int total_first;<br>
total=0;<br>
total_first=0;<br>
String product_name;<br>
int product_price;<br>
int product_discount;<br>
int product_first;<br>
int cart_quantity;<br>
<br>
if (rs.next()){<br>
while (rs.next()) {<br>
product_id=java.lang.Integer.parseInt(rs.getString(1));<br>
product_name=rs.getString(2);<br>
product_price=java.lang.Integer.parseInt(rs.getString(3));<br>
product_discount=java.lang.Integer.parseInt(rs.getString(4));<br>
cart_quantity=java.lang.Integer.parseInt(rs.getString(5));<br>
product_first=java.lang.Integer.parseInt(rs.getString(6));<br>
%&gt;<br>
<br>
&lt;tr&gt;<br>
&lt;td width=&quot;10%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_name%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;10%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_price%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;10%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_discount%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;10%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;input type=&quot;text&quot; name=&quot;&lt;%= &quot;t&quot; + product_id %&gt;&quot; size=&quot;3&quot; value=&quot;&lt;%=cart_quantity%&gt;&quot;&gt;&lt;/td&gt;<br>
&lt;td width=&quot;14%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_discount*cart_quantity%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;12%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_first + &quot;%&quot;%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;17%&quot; height=&quot;1&quot; align=&quot;left&quot;&gt;&lt;%=product_first*product_discount*cart_quantity/100.0%&gt;&lt;/td&gt;<br>
&lt;td width=&quot;17%&quot; height=&quot;1&quot;&gt;&lt;div align=&quot;center&quot;&gt;&lt;center&gt;&lt;p&gt;&lt;a href=&quot;shop_cart.jsp?action=delete&amp;product_id=&lt;%=product_id%&gt;&quot;&gt;delete&lt;/a&gt;&lt;/td&gt;<br>
&lt;/tr&gt;<br>
<br>
&lt;%<br>
total=total+product_discount*cart_quantity;<br>
total_first=total_first+product_discount*cart_quantity*product_first/100;<br>
}<br>
%&gt;<br>
<br>
&lt;tr align=&quot;center&quot;&gt;<br>
&lt;td width=&quot;72%&quot; colspan=&quot;6&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;right&quot;&gt;&lt;p&gt;总计&lt;/td&gt;<br>
&lt;td width=&quot;36%&quot; colspan=&quot;2&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;left&quot;&gt;&lt;%=total%&gt;&lt;/td&gt;<br>
&lt;/tr&gt;<br>
&lt;tr align=&quot;center&quot;&gt;<br>
&lt;td width=&quot;72%&quot; colspan=&quot;6&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;right&quot;&gt;&lt;p&gt;定金总计&lt;/td&gt;<br>
&lt;td width=&quot;36%&quot; colspan=&quot;2&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;left&quot;&gt;&lt;%=total_first%&gt;&lt;/td&gt;<br>
&lt;/tr&gt;<br>
&lt;tr align=&quot;center&quot;&gt;<br>
&lt;td width=&quot;72%&quot; colspan=&quot;6&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;right&quot;&gt;&lt;p&gt;结余&lt;/td&gt;<br>
&lt;td width=&quot;36%&quot; colspan=&quot;2&quot; height=&quot;16&quot;&gt;&lt;div align=&quot;left&quot;&gt;&lt;%=total-total_first%&gt;&lt;/td&gt;<br>
&lt;/tr&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/table&gt;<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&lt;/center&gt;&lt;/div&gt;<br>
<br>
&lt;%<br>
}else{<br>
%&gt;<br>
&lt;p align=&quot;center&quot;&gt;购物车为空!&lt;/p&gt;<br>
&lt;%<br>
}<br>
%&gt;<br>
<br>
<br>
<br>
数据库操作部分<br>
<br>
程序用到两个表：<br>
1 shop_cart表<br>
&nbsp;&nbsp;&nbsp;&nbsp;cart_id int&nbsp;&nbsp;购物车编号&nbsp;&nbsp;自动编号<br>
&nbsp;&nbsp;&nbsp;&nbsp;cart_shop_id&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商店编号<br>
&nbsp;&nbsp;&nbsp;&nbsp;cart_product_id&nbsp;&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品编号<br>
&nbsp;&nbsp;&nbsp;&nbsp;cart_quantity&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品数量<br>
临时存放购物车数据<br>
<br>
2 shop_product表<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_id&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品编号&nbsp;&nbsp;&nbsp;自动编号<br>
&nbsp;&nbsp;&nbsp;&nbsp;shop_id&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;商店编号<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_name&nbsp;&nbsp;&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品名称<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_bb&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品介绍<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_price&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;市场价<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_discount&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;优惠价<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_img&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;img&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;图片<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_status&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nvarchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;状态<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_first&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;int&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;定金比例<br>
&nbsp;&nbsp;&nbsp;&nbsp;product_type&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nvanchar&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;商品类型<br>
存放商品资料<br>
<br>
使用bka.java制成的javabean：bka.class可以提供对数据库的操作。<br>
<br>
另外，需在控制面板的系统DSN中注册bka.dsn，<br>
从而可使JSP通过JDBC-ODBC来调用sql数据库。<br>
在页面中调用javabean，基本上可采用以下方式：<br>
<br>
<br>
&lt;%@ page language=&quot;java&quot; import=&quot;java.sql.*&quot; %&gt;<br>
&lt;jsp:useBean id=&quot;RegisterBean&quot; scope=&quot;page&quot; class=&quot;shop.bka&quot; /&gt;<br>
&lt;%<br>
String sql=&quot;select * from xxx&quot;;<br>
ResultSet rs = RegisterBean.executeQuery(sql); <br>
if(rs.next()) { <br>
rs.close();<br>
RegisterBean.closeStmt();<br>
session.putValue(&quot;register_message&quot;,&quot;duplicate name found!&quot;);<br>
}<br>
%&gt;<br>
注意应在使用后将rs关闭。<br>
<br>
<br>
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.<br>
<br>
--shop/bka.java--<br>
<br>
<br>
package shop;<br>
import java.sql.*;<br>
<br>
public class bka {<br>
String sDBDriver = &quot;sun.jdbc.odbc.JdbcOdbcDriver&quot;;<br>
String sConnStr = &quot;jdbc:odbc:bka&quot;;<br>
Connection conn = null;<br>
ResultSet rs = null;<br>
<br>
public bka() {<br>
try {<br>
Class.forName(sDBDriver); <br>
}<br>
catch(java.lang.ClassNotFoundException e) {<br>
System.err.println(&quot;bka(): &quot; + e.getMessage());<br>
}<br>
}<br>
<br>
public ResultSet executeQuery(String sql) {<br>
rs = null;<br>
try {<br>
conn = DriverManager.getConnection(sConnStr,&quot;xxx&quot;,&quot;yyy&quot;); <br>
Statement stmt = conn.createStatement();<br>
rs = stmt.executeQuery(sql);<br>
} <br>
catch(SQLException ex) { <br>
System.err.println(&quot;aq.executeQuery: &quot; + ex.getMessage());<br>
}<br>
return rs;<br>
}<br>
}<br>
<br>

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