// Fig. 16.37: UpdateCartServlet.java
// Changes quantity of an item in shopping cart
package cartXML;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
import java.sql.*;

public class UpdateCartServlet extends HttpServlet {

   public void service( HttpServletRequest req,
      HttpServletResponse res )
      throws ServletException, IOException
   {
      HttpSession session = req.getSession( true );
      ShoppingCart cart = ( ShoppingCart ) session.getAttribute(
         "cart" );
      ServletContext sc = getServletConfig()
         .getServletContext();

      if ( cart.getUsername() == null ) {
         sc.getRequestDispatcher( "/index.wml" )
            .forward( req, res );
         return;
      }

      String productID =  req.getParameter( "productID" );
      int bookElement = cart.contains( productID );
      int quantity = Integer.parseInt( req.getParameter(
         "quantity" ) );

      if ( quantity == 0 )
         cart.remove( bookElement );
      else
         cart.setQuantity( bookElement, quantity );

      session.setAttribute( "cart", cart );
      sc.getRequestDispatcher( "/servlet/cartXML.ViewCartServlet" )
         .forward( req, res );
   }

}

/*
 **************************************************************************
 * (C) Copyright 2001 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
 **************************************************************************
*/