仅在刷新页面后加载Cookie [英] Cookies only loaded after refreshing page
问题描述
我真的很抱歉，这是关于Cookie的第二个或第三个问题，但老实说，我不明白为什么会发生这种情况...
在登录页面上，我通过以下方式设置Cookie:
I''m truly sorry, this is the second or third question about cookies, but honestly I can''t understand why this happens...
On the login page I set the cookie this way:
Cookie cookie = new Cookie("username", user);
cookie.setMaxAge(365 * 24 * 60 * 60);
response.addCookie(cookie);
然后将用户重定向到其他页面.
除了以下内容，我删除了几乎所有代码(以确保没有冲突):
And then user is redirected to a different page.
I deleted almost all my code (to make sure there are no conflicts), except this:
<%@page import="javax.servlet.http.Cookie"%>
<html>
<%
Cookie cookies[] = request.getCookies();
Cookie nome = null;
Cookie aux_login = null;
int auxiliar = 0;
Cookie idaux = null;
String jog1="",jog2="";
if (cookies != null) {
for (int i = 0; i < cookies.length; i++) {
out.println("<br>"+cookies[i].getName()+" <br>");
if (cookies[i].getName().equals("username")) {
nome = cookies[i];
}
if (cookies[i].getName().equals("aux_login")) {
aux_login = cookies[i];
}
if (cookies[i].getName().equals("idsala")) {
idaux = cookies[i];
}
}
}
out.println("ARE NULL ??");
if (nome == null) {
out.println("Cookie ''username'' nao encontrada");
else
welcome nome.getValue()...
}
因此，在第一次加载时未找到Cookie(已验证nome == null)，但是如果刷新页面，便会找到它们-因此它们存在，但在第一次加载时它们未被检测到...
我究竟做错了什么?考虑一下这件事，如果页面相同，那将是正常的(当然会显示信息)，但是页面却是不同的...
So at the first load cookies are not found (that nome == null is verified), but if I refresh the page they are found - so they exist, but in a first load they are not being detected...
What am I doing wrong? Thinking about the matter this would be normal (the information displayed of course) if the page was the same, but it''s a different page...
推荐答案
您应该使用path为该Cookie添加域.默认情况下，cookie仅对该页面有效(在这种情况下为登录页面).有关更多信息(并查看路径，应添加;path=/):
http://javascript.about.com/library/blwcookie.htm [ http://www.tutorialspoint.com/jsp/jsp_cookies_handling.htm [
You should add the domain for that cookie usingpath. By default a cookie is only valid for that page only (in this case the login page). For more info (and have a look at path, you should add;path=/):
http://javascript.about.com/library/blwcookie.htm[^]
For JSP have a look atsetDomain:
http://www.tutorialspoint.com/jsp/jsp_cookies_handling.htm[^]
Good luck!
我想我知道发生了什么事，我的登录页面是index.jsp，我的第二页"是default.jsp(是的，我知道这是不好的做法，但是我只是学习JSP几天，请给我一些时间:)).因此，我尝试这样做:
I think i know what''s happening, my login page is index.jsp and my "second page" is default.jsp (yes I know this is bad practice, but I''m just learning JSP for a few days, give me time :) ). So, I tried to do:
if (nome == null) {
out.println("Cookie 'username' nao encontrada");
and with js script..
window.location.reload();
我被重定向到index.jsp.多数民众赞成在我登录成功(并转到default.jsp)时发现我的URL仍然是(出于某种动机！)index.jsp.
看起来像是因为这样进行重定向:
I was redirectedto index.jsp. Thats when I noticed when I do a sucessfull login (and go to default.jsp) my URL is still (for some motive!!) index.jsp.
Looks like its because doing the redirect this way:
<jsp:forward page="/default.jsp" />
<%
使用response.sendRedirect("default.jsp");
解决的问题
请注意，上一页的request.getParameter("t1")将不再起作用.
附注:使用会话进行身份验证总是更安全.
Problem solved with response.sendRedirect("default.jsp");
Be advised that request.getParameter("t1") from previous page will not work anymore.
P.S: It''s always safer use sessions for authentication.
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