Use hidden fields to save session data : Session « Servlets « Java

Use hidden fields to save session data


import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ShoppingCartViewerHidden extends HttpServlet {

  public void doGet(HttpServletRequest req, HttpServletResponse res)
                               throws ServletException, IOException {
    PrintWriter out = res.getWriter();

    out.println("<HEAD><TITLE>Current Shopping Cart Items</TITLE></HEAD>");

    // Cart items are passed in as the item parameter.
    String[] items = req.getParameterValues("item");

    // Print the current cart items.
    out.println("You currently have the following items in your cart:<BR>");
    if (items == null) {
    else {
      for (int i = 0; i < items.length; i++) {
        out.println("<LI>" + items[i]);

    // Ask if the user wants to add more items or check out.
    // Include the current items as hidden fields so they'll be passed on.
    out.println("<FORM ACTION=\"/servlet/ShoppingCart\" METHOD=POST>");
    if (items != null) {
      for (int i = 0; i < items.length; i++) {
        out.println("<INPUT TYPE=HIDDEN NAME=\"item\" VALUE=\"" +
          items[i] + "\">");
    out.println("Would you like to<BR>");
    out.println("<INPUT TYPE=SUBMIT VALUE=\" Add More Items \">");
    out.println("<INPUT TYPE=SUBMIT VALUE=\" Check Out \">");



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