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."; } }