在jsp中获取cookie值

Question

on my Java servlet I've initialized a cookie as below,

String timeStamp = new SimpleDateFormat("dd:MM:yyyy_HH:mm:ss:SSS").format(Calendar.getInstance().getTime());
timeStamp = timeStamp + ":" + System.nanoTime();
String loc = "/u/poolla/workspace/FirstServlet/WebContent/WEB-INF/"+timeStamp;
Cookie thecookie = new Cookie("thecookie", loc);
thecookie.setMaxAge(60*60*24);
response.addCookie(thecookie);

and in cookie comments I've added some data as below,

thecookie.setComment(fileTxt);

Now on my jsp page when I try to access this comment it returned a null,

 <%
    Cookie my = null;
    my.getComment();%>

How do I get the comment value set in java to my jsp page??

Answer 1

In your JSP use,

<%
   Cookie cookie = null;
   Cookie[] cookies = null;
   cookies = request.getCookies();
    if( cookies != null)
      {
      for (int i = 0; i < cookies.length; i++){
         cookie = cookies[i];
         String b = cookie.getComment();
     request.setAttribute("xyz", b);
     }
     }
%>

and then you can use is by ${xyz} in htmls and use b if you want to use it in JSP code.

Answer 2

You are setting my to null and accessing the comment. This will throw NullPointerException .Change your code to

    <%
    Cookie[] my = request.getCookies();
    for(int i=0;i<my.length;i++){
    String comment = my[i].getComment();
    out.println(comment);
    }
    %>

Note : Please avoid using Scriptlets . they are NOT recommended

Answer 3

Cookie : cookie['cookie_name']

Cookie Value : cookie['cookie_name'].value