第一次在这里发帖，我希望这是一个有效的问题。我一直在构建一个基本的 Java servlet，它从页面上的表单中接受 3 个名称/值对，将它们设置为 1. 请求属性 2. 会话属性和 3. cookie 属性。然后将 Cookie 添加到响应中，然后转发视图 (AccountSettings.jsp)。AccountSettings 页面应该使用 request.getCookies() 将它们转储到数组中，然后从数组中读取值。每次我使用此表格时，所有这些都应该发生。
我的问题是 cookie 值仅在我第一次使用表单时正确，然后每次我再次使用表单时，cookie 都会显示页面加载时输入的最后一个值。但是，如果我刷新页面，cookie 值将正确显示。我尝试手动删除 Logout servlet 中的 cookie（setMaxAge(0) 然后重新添加到响应），但这只会在索引 1 处产生一个常量 ArrayOutOfBoundsException，所以我将这部分注释掉并单独留下 cookie。
显示页面后，我在 Chrome 中检查了与 localhost 关联的 cookie，并且值设置正确，因此在我看来，JSP 是在实际正确设置 cookie 之前绘制的。
任何有关如何解决此问题的帮助将不胜感激。这是我的代码。
小服务程序：
public class Login extends HttpServlet {
private static final long serialVersionUID = 1L;
public Login() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
login(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
login(request, response);
}
private void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
// get a new or existing session
HttpSession session = request.getSession();
// Instantiate user and populate values
User user = new User();
user.setUser(request.getParameter("user"));
user.setPass(request.getParameter("pass"));
// Get last page
String referringUrl = request.getParameter("referringPage");
session.setAttribute("user", user.getUser());
session.setAttribute("pass", user.getPass());
session.setAttribute("lastPage", referringUrl);
Cookie cookie1 = new Cookie("user", user.getUser());
Cookie cookie2 = new Cookie("pass", user.getPass());
Cookie cookie3 = new Cookie("lastPage", referringUrl);
response.addCookie(cookie1);
response.addCookie(cookie2);
response.addCookie(cookie3);
request.setAttribute("user", user.getUser());
request.setAttribute("pass", user.getPass());
request.setAttribute("lastPage", referringUrl);
try{
if (user.authorize()){
session.setAttribute("name", user.getName());
session.setAttribute("authorized", "1");
}else{
session.setAttribute("authorized", "0");
}
}
catch(Exception e){
e.printStackTrace();
}
RequestDispatcher view = request.getRequestDispatcher("AccountSettings.jsp");
view.forward(request, response);
user.destroy();
}
}
看法：
<div id="content">
<div class="padding">
<%
if (!loggedIn){
out.print(
"Oops! I'm not sure how you got here..."
);
}else{
Cookie[] cookies = request.getCookies();
out.print(
"<h2>Account Settings</h2><br><br>" +
"<table>" +
"<tr>" +
"<th>Source</th>" +
"<th>Username</th>" +
"<th>Password</th>" +
"<th>Last Page Visted</th>" +
"</tr>" +
"<tr>" +
"<th>Request</th>" +
"<td>" + request.getAttribute("user") + "</td>" +
"<td>" + request.getAttribute("pass") + "</td>" +
"<td>" + request.getAttribute("lastPage") + "</td>" +
"</tr>" +
"<tr>" +
"<th>Session</th>" +
"<td>" + session.getAttribute("user") + "</td>" +
"<td>" + session.getAttribute("pass") + "</td>" +
"<td>" + session.getAttribute("lastPage") + "</td>" +
"</tr>" +
"<tr>" +
"<th>Cookies</th>" +
"<td>" + cookies[1].getValue() + "</td>" +
"<td>" + cookies[2].getValue() + "</td>" +
"<td>" + cookies[3].getValue() + "</td>" +
"</tr>" +
"</table>"
);
}
%>
</div>
</div>