<%@ page import="java.util.*" %>
Widget Inc.
Widget Inc. Online Shopping
<% Map cart;
if (session.isNew()) {
cart = new TreeMap();
session.setAttribute("cart", cart);
} else
cart = (Map)session.getAttribute("cart");
if (request.getMethod().equals("POST")) {
String item = request.getParameter("item");
String amount = request.getParameter("amount");
if (item!=null) {
try {
addToCart(cart, item, Integer.parseInt(amount));
} catch (Exception e) {
response.sendError(response.SC_BAD_REQUEST,
"malformed request");
}
}
}
String url = request.getRequestURI();
%>
<% if (cart.isEmpty()) { %>
Your shopping cart is empty.
<% } else { %>
Your shopping cart now contains:
| Item | Amount
<% Iterator i = cart.entrySet().iterator();
while (i.hasNext()) {
Map.Entry me = (Map.Entry)i.next();
%>
|
|---|
| <%= me.getKey() %>
| <%= me.getValue() %>
<% }%>
|
<% }%>
<%! void addToCart(Map cart, String item, int amount) {
if (amount<0)
return;
Integer a = (Integer)cart.get(item);
if (a==null)
a = new Integer(0);
cart.put(item, new Integer(a.intValue()+amount));
}
%>