problem updating quantity field

[John Schretz]

I am trying a modified example from a book. It is a shopping cart page. When i hit the update quantity button on the first line item the quantity updates correctly. Any other line item below that doesnt update. I have the form tags outside of the loop right now. I tried putting the form tags within the loop and i can then update all the line items. However in the book example the form tags are outside of the loop. Which is the corrcet way to do this? is it ok to have multiple form tags within the loop or is there a better way to do this?



JSP code

             <c:forEach var="item" items="${cart.items}">
 
            <!--LINE ITEM-->
              <table width="100%" height="25" border="0" cellpadding="2" cellspacing="2" >
                <tr>
                  <td height="25" align="left" valign="top">
                  <table width="100%" height="25" cellpadding="0" cellspacing="0" style="border: 1px solid #787878">
                    <tr>
                      <td height="25" align="left" valign="top">
                      <table width="100%" height="25" border="0" cellpadding="0" cellspacing="0">
                        <tr>
                          <td width="62" rowspan="3" align="center" valign="middle">
                          
                          <!--ADD ITEM TABLE-->
                          <table width="55%" border="0" cellspacing="1" cellpadding="1">
                            <tr>
                              <td>
                              <img src="prodImages/${item.product.imageT1}" width="54" height="72" />
                              </td>
                            </tr>
                          </table>
                          </td>
                          <td height="30" colspan="4" align="left" valign="top" class="formfont">
                          ${item.product.desc2} ${item.product.size} ${item.product.attribute}<br />
                          ${item.product.brand}
                          </td>
                        </tr>
                        <tr>
                          <td width="108" class="style2">
                           <label for="user" class="form">${item.product.priceCurrencyFormat} X</label>
                           <input type="hidden" name="select" value="${item.product.itemNum}">
                           <input type="text" name="quantity" value="${item.quantity}" class="form"/>
                          </td>
                          <td width="65" height="19" class="trailer" >
                           = <span style="color: #FF0000">${item.totalCurrencyFormat}</span>                         
                          </td>
                          <td width="112" rowspan="2" align="left" valign="top" class="style2">
                           <input type="image" src="images/update_up.gif" alt="" width="105" height="34" class="domroll images/update_over.gif" border="0" value="Update"/> 
                          </td>
                          <td width="359" rowspan="2" align="left" valign="top" class="style2">
                           <input type="image" src="images/remove_up.gif" alt="" width="85" height="35" class="domroll images/remove_over.gif" border="0" name="removeButton" value="Remove"/> 
                          </td>
                        </tr>
                        <tr>
                          <td align="left" valign="middle" class="style2"> </td>
                          <td height="21" align="left" valign="middle" class="style2"> </td>
                        </tr>
                      </table>
                      <!--END ADD ITEM TABLE-->
                      
                      </td>
                    </tr>
                  </table>
                  </td>
                </tr>
              </table>
                 
               </c:forEach>

Servlet

package cart;
 
import javax.servlet.http.HttpServlet;
import java.io.*;
import java.util.ArrayList;
 
import javax.servlet.*;
import javax.servlet.http.*;
 
import data.ProductDB;
 
import ecom.Cart;
import ecom.LineItem;
import ecom.Product;
 
 
public class DisplayCartServlet extends HttpServlet
{
HttpSession session;
 
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
 
String itemnum = request.getParameter("select");
String quantityString = request.getParameter("quantity");
String removeButtonValue = request.getParameter("removeButton");
 
session = request.getSession();
 
Cart cart =  (Cart) session.getAttribute("cart");  
if (cart == null)
{
cart = new Cart();
session.setAttribute("cart", cart);
}
 
// If the user enters a negative or invalid number in the
// Update text box, the quantity is automatically reset to 1.
int quantity = 1;
try
{
quantity = Integer.parseInt(quantityString);
if (quantity < 0)
quantity = 1;
}
catch(NumberFormatException nfe)
{
quantity = 1;
}
 
// If the user clicks the Remove button
if (removeButtonValue != null)
{
quantity = 0;
}
 
// Get product from product code
 
Product product = ProductDB.selectItem(itemnum);
session.setAttribute("product", product);
 
// If product exists, add or remove from cart
if (product != null)
{
LineItem lineItem = new LineItem();
lineItem.setProduct(product);
lineItem.setQuantity(quantity);
if (quantity > 0){
cart.addItem(lineItem);
}
else{
cart.removeItem(lineItem);
}
}
session.setAttribute("cart", cart);
 
calcTotals(cart);
 
String url = "";
url = "/cart.jsp";
 
RequestDispatcher dispatcher =
getServletContext().getRequestDispatcher(url);
dispatcher.forward(request, response);
}
 
public void calcTotals(Cart cart){
 
String tax = "";
String ship = "";
 
double subTotal = 0;
 
ArrayList <LineItem> items = cart.getItems();
 
for (int i = 0; i < items.size(); i++)
{
LineItem lineItem = items.get(i);
subTotal = subTotal + lineItem.getTotal();
}
session.setAttribute("sub", subTotal);
session.setAttribute("tax", tax);
session.setAttribute("ship", ship);
session.setAttribute("total", subTotal);
}
 
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException
{
doPost(request, response);
}
}

[ September 22, 2008: Message edited by: John Schretz ]