ReceiptServlet.java

 

 /*
  *
  * 
  */
 
 import java.io.*;
 import java.util.*;
 import javax.servlet.*;
 import javax.servlet.http.*;
 import cart.ShoppingCart;
 import database.*;
 import exception.*;
 
 /**
  * An HTTP servlet that responds to the POST method of the HTTP protocol.
  * The Receipt servlet updates the book database inventory, invalidates the user session, 
  * thanks the user for the order. */
 
 public class ReceiptServlet extends HttpServlet { 
 
   private BookDB bookDB;
 
   public void init() throws ServletException {
     bookDB =
           (BookDB)getServletContext().getAttribute("bookDB");
     if (bookDB == null)
         throw new UnavailableException("Couldn't get database.");
   }
 
   public void destroy() {
         bookDB = null;
   }
   public void doPost(HttpServletRequest request,
                       HttpServletResponse response) throws ServletException, IOException
   {
     boolean orderCompleted = true;
     // Get the user's session and shopping cart
     HttpSession session = request.getSession(true);
     ResourceBundle messages = (ResourceBundle)session.getAttribute("messages");
     ShoppingCart cart =
       (ShoppingCart)session.getAttribute("cart");
     if (cart == null) {
       cart = new ShoppingCart();
       session.setAttribute("cart", cart);
     }
     // Update the inventory
     try {
       bookDB.buyBooks(cart);
     } catch (OrderException e) {
       System.err.println(e.getMessage());
       orderCompleted = false;
     }
 
     // Payment received -- invalidate the session
     session.invalidate();
     
     // set content type header before accessing the Writer
     response.setContentType("text/html");
     response.setBufferSize(8192);
     PrintWriter out = response.getWriter();
     
     // then write the response
     out.println("<html>" +
                 "<head><title>" + messages.getString("TitleReceipt") + "</title></head>" );
 
     // Get the dispatcher; it gets the banner to the user
     RequestDispatcher dispatcher =
       getServletContext().getRequestDispatcher("/banner");
                                     
     if (dispatcher != null)
         dispatcher.include(request, response);
        
     if (orderCompleted)              
       out.println("<h3>" + messages.getString("ThankYou") +
           request.getParameter("cardname") + ".");
     else
       out.println("<h3>" + messages.getString("OrderError"));     
 
     out.println("<p> &nbsp; <p><strong><a href=\"" +
         response.encodeURL(request.getContextPath()) +
         "/enter\">" + messages.getString("ContinueShopping") + "</a> &nbsp; &nbsp; &nbsp;" +
         "</body></html>");
     out.close();
   }
 
   public String getServletInfo() {
       return "The Receipt servlet updates the book database inventory, invalidates the user session, " +
               "thanks the user for the order.";
   }
 }