我有一个无框架的Web应用程序。我需要使用会话来实现一种检查不成功登录的简单方法。如果用户尝试使用不正确的用户名/密码组合登录3次，则会给他们20分钟的超时时间，然后才能再次尝试登录。

当前，只有在用户成功登录系统后，我才设置用户会话。但是，似乎我也应该在未成功登录的情况下进行会话，并以某种方式计算登录尝试次数。

Login.jsp（简体版）：

<form name="loginForm" method="post" action="CustomerData">
User name:<input type="text" name="userName"/>
Password:<input type="password" name="password"/>
<input type="button" value="submit">

CustomerData.java（简化版）：

// See if customer is a valid user
        String selectQuery = "Select firstName,lastName,email from customer where userName='"+userName+"' and password='"+password+"'";
        selectResult = statement.executeQuery(selectQuery);

if(selectResult.next())
{
    // We got a valid user, let's log them in
    ....
    HttpSession session = request.getSession(true);
    session.setAttribute("customer", customer);
}
else
{
    // this is where I need to get the session id (??),
    // count the unsuccessful login attempts somehow, 
    //and give them a 20 minutes timeout before they can try logging in again.

    request.setAttribute("message","Invalid username or password. Please try again!");

}

在进行研究时，我发现各种Java框架都有很多内置的安全功能。我还发现使用会话不是跟踪登录尝试的最佳方法，因为用户可以使用不同的浏览器登录。但是，我正在为一个永远不会进入任何生产环境的简单Web项目创建此功能。我想知道如何使用Java
HTTPSession对象实现此功能。

好的，这是我收到的反馈的完整解决方案。我发布此信息是为了防止其他人遇到类似问题：

// See if customer is a valid user
String selectQuery = "Select firstName,lastName,email from customer where userName='"+userName+"' and password='"+password+"'";
selectResult = statement.executeQuery(selectQuery);

        if(selectResult.next())
        {
            // We got a valid user, let's log them in
            Customer customer = new Customer();
            customer.setFirstName(selectResult.getString("firstName"));
            customer.setLastName(selectResult.getString("lastName"));
            customer.setEmail(selectResult.getString("email"));
            customer.setUserName(userName);
            customer.setPassword(password);

            // establish a user session
            session.setAttribute("customer", customer);
            session.setAttribute("firstName", customer.getFristName());
            url = "/index.jsp";
            selectResult.close();

        }
        else
        {
            int loginAttempt;
            if (session.getAttribute("loginCount") == null)
            {
                session.setAttribute("loginCount", 0);
                loginAttempt = 0;
            }
            else
            {
                 loginAttempt = (Integer) session.getAttribute("loginCount");
            }

            //this is 3 attempt counting from 0,1,2
            if (loginAttempt >= 2 )
            {        
                long lastAccessedTime = session.getLastAccessedTime();
                date = new Date();
                long currentTime = date.getTime();
                long timeDiff = currentTime - lastAccessedTime;
                // 20 minutes in milliseconds  
                if (timeDiff >= 1200000)
                {
                    //invalidate user session, so they can try again
                    session.invalidate();
                }
                else
                {
                     // Error message 
                     session.setAttribute("message","You have exceeded the 3 failed login attempt. Please try loggin in in 20 minutes, or call our customer service center at 1-800 555-1212.");
                }

            }
            else
            {
                 loginAttempt++;
                 int allowLogin = 3-loginAttempt;
                 session.setAttribute("message","loginAttempt= "+loginAttempt+". Invalid username or password. You have "+allowLogin+" attempts remaining. Please try again! <br>Not a registered cusomer? Please <a href=\"register.jsp\">register</a>!");
            }
            session.setAttribute("loginCount",loginAttempt);
            url = "/login.jsp";

        }

        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(url);
        dispatcher.forward(request, response);