Java by API/java.rmi.server/UID — различия между версиями

Материал из Java эксперт
Перейти к: навигация, поиск
м (1 версия)
 
(нет различий)

Текущая версия на 14:48, 31 мая 2010

new UID()

import java.io.IOException;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ShoppingCartViewerRewrite extends HttpServlet {
  public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
      IOException {
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();
    out.println("<HEAD><TITLE>Current Shopping Cart Items</TITLE></HEAD>");
    out.println("<BODY>");
    // Get the current session ID, or generate one if necessary
    String sessionid = req.getPathInfo();
    if (sessionid == null) {
      sessionid = generateSessionId();
    }
    // Cart items are associated with the session ID
    String[] items = getItemsFromCart(sessionid);
    // Print the current cart items.
    out.println("You currently have the following items in your cart:<BR>");
    if (items == null) {
      out.println("<B>None</B>");
    } else {
      out.println("<UL>");
      for (int i = 0; i < items.length; i++) {
        out.println("<LI>" + items[i]);
      }
      out.println("</UL>");
    }
    // Ask if the user wants to add more items or check out.
    // Include the session ID in the action URL.
    out.println("<FORM ACTION=\"/servlet/ShoppingCart/" + sessionid + "\" METHOD=POST>");
    out.println("Would you like to<BR>");
    out.println("<INPUT TYPE=SUBMIT VALUE=\" Add More Items \">");
    out.println("<INPUT TYPE=SUBMIT VALUE=\" Check Out \">");
    out.println("</FORM>");
    // Offer a help page. Include the session ID in the URL.
    out.println("For help, click ");
    out.println("</BODY></HTML>");
  }
  private static String generateSessionId() throws UnsupportedEncodingException {
    String uid = new java.rmi.server.UID().toString(); // guaranteed unique
    return URLEncoder.encode(uid, "UTF-8"); // encode any special chars
  }
  private static String[] getItemsFromCart(String sessionid) {
    return new String[] { "a", "b" };
  }
}


Источник — «http://jexp.ru/index.php?title=Java_by_API/java.rmi.server/UID&oldid=2660»