cookie application problem

windwhisper · Post time: 2020-1-21 17:40:01

Initially contacted cookies, and wrote a small program according to the example in the book, but why does n’t cookie-AccessTimes reset to 1 each time I reset resetCookie.jsp? (Now accumulates 1 for each refresh)

The code is very simple, I will post it here in full.
resetCookie.jsp:
<% @ page language = "java"%>
<% @ page pageEncoding = "GB2312"%>
<html>
    <head>
        <title> jsp session tracking </ title>
    </ head>
    <body>
        <%
        response.addCookie (new Cookie ("AccessTimes", "1"));
        %>
        <jsp: forward page = "useCookie.jsp" />
    </ body>
</ html>

useCookie.jsp:
<% @ page pageEncoding = "GB2312" language = "java"%>
<html>
    <head>
        <title> cookie demo </ title>
    </ head>
    <body>
        <%
        Cookie [] cookies = request.getCookies ();
        String counter_S = null;
        int counter;
        if (cookies! = null)
        {
                for (int i = 0; i <cookies.length; i ++)
                {
                        if (cookies [i] .getName (). equals ("AccessTimes"))
                                counter_S = cookies [i] .getValue ();
                }
                try
                {
                                counter = Integer.parseInt (counter_S) +1;
                }
                catch (Exception ex)
                {
                        counter = 1;
                }
                response.addCookie (new Cookie ("AccessTimes", new Integer (counter) .toString ()));
                out.println ("You have visited the site for" + counter + "times!");
        }
        %>
    </ body>
</ html>

chen96542 · Post time: 2020-1-31 14:00:02

jsp: forward page = "useCookie.jsp";
The problem here is that the forward method will forcibly flush the buffer of the output stream, that is, the header set before and the output performed are not performed normally.

windwhisper · Post time: 2020-2-9 16:00:02

Looking at the documentation, the statement following jsp: forward will not be executed.
Moreover, there is no output statement before jsp: forward, response.addCookie is not an output. The document says that there will be an exception if there is an output before, but there is no exception in mine.

windwhisper · Post time: 2020-2-9 20:15:01

After searching on the Internet, there are indeed statements that reflect jsp: forward cannot be executed
Can you explain the prawns

windwhisper · Post time: 2020-2-17 22:30:01

The previous statement of jsp: forward could not be executed

tellyou · Post time: 2020-2-20 22:00:01

The simplest, change the redirect

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