2017.9.28 web设计简单的购物车应用案例--session的简单应用

该购物过程是在session范围内完成的，需要使用session对象实现信息的共享

（1）购买“肉类”商品的页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
    <head>
        <title>购物肉类商品页面</title>
    </head>
    <body>
        <% request.setCharacterEncoding("UTF-8");
            if(request.getParameter("c1")!=null)
                session.setAttribute("s1",request.getParameter("c1"));
            if(request.getParameter("c2")!=null)
                session.setAttribute("s2",request.getParameter("c2"));
            if(request.getParameter("c3")!=null)
                session.setAttribute("c3",request.getParameter("c3"));
        %>
        各种肉类大甩卖，一律十块：<br>
        <form method="post" action="ch03_18_buy1.jsp">
            <p><input type="checkbox" name="c1" value="猪肉">猪肉&nbsp;
               <input type="checkbox" name="c2" value="牛肉">牛肉&nbsp;
               <input type="checkbox" name="c3" value="羊肉">羊肉&nbsp;
            </p>
            <p><input type="submit" value="提交" name="B1">
                <a href="ch03_18_buy2.jsp">买点别的</a>&nbsp;
                <a href="ch03_ 18_display.jsp">查看购物车</a>&nbsp;
            </p>
        </form>
    </body>
</html>

（2）购买“球类”商品的页面

<%@page language="java" import="java.util.*" pageEncoding="UTF-8" %>
<html>
    <head>
        <title>购买球类页面</title>
    </head>
    <body>
        <%request.setCharacterEncoding("UTF-8");
            if(request.getParameter("b1")!=null)
                session.setAttribute("s4",request.getParameter("b1"));
            if(request.getParameter("b2")!=null)
                session.setAttribute("s5",request.getParameter("b2"));
            if(request.getParameter("b3")!=null)
                session.setAttribute("s6",request.getParameter("b3"));
         %>
         各种球大甩卖，一律八块：
         <form method="post" action="ch03_18_buy2.jsp">
         <p>
             <input type="checkbox" name="b1" value="篮球">篮球&nbsp;
             <input type="checkbox" name="b2" value="足球">足球&nbsp;
             <input type="checkbox" name="b3" value="排球">排球&nbsp;
         </p>
         <p>
             <input type="submit"  name="x1"value="提交">
             <a href="ch03_18_buy1.jsp">买点别的</a>&nbsp;
             <a href="ch03_18_buy2.jsp">查看购物车</a>&nbsp;
         </form>
    </body>
</html>

（3）显示购物车信息的页面

<%@page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
    <head>
        <title>显示购物车购物信息</title>
    </head>
    <body>
        你的选择结果是：<br>
        <%request.setCharacterEncoding("UTF-8");
            String str="";
            if(session.getAttribute("s1")!=null)
            {
                str=(String)session.getAttribute("s1");
                out.println(str+"<br>");
            }
            if(session.getAttribute("s2")!=null);
            {
                str=(String)session.getAttribute("s2");
                out.print(str+"<br>");
            }
            if(session.getAttribute("s3")!=null)
            {
                str=(String)session.getAttribute("s3");
                out.print(str+"<br>");
            }
            if(session.getAttribute("s4")!=null)
            {
                str=(String)session.getAttribute("s4");
                out.print(str+"<br>");
            }
            if(session.getAttribute("s5")!=null)
            {
                str=(String)session.getAttribute("s5");
                out.print(str+"<br>");
            }
            if(session.getAttribute("s6")!=null)
            {
                str=(String)session.getAttribute("s6");
                out.print(str+"<br>");
            }
         %>
    </body>
</html>