JSP：关于具有约束登录状态的系统中的会话

Question

When I am doing a project requires a login in system, I found that jsp will automatically create session, so I add <%@ page session="false" %> into all pages to disable their abilities to create session since I only want one servlet to be able to create session. 当我做一个项目需要在系统中登录时，我发现jsp会自动创建会话，因此我在所有页面中添加<％@ page session =“ false”％>以禁用其创建会话的能力，因为我只想要一个servlet能够创建会话。

However, when it comes to using bean, I found that, I can't use bean with session scope because of <%@ page session="false" %>, I would like to ask what is the possible solution to solve this deadlock. 但是，在使用bean时，我发现由于<％@ page session =“ false”％>而无法在会话范围内使用bean，我想问一下解决此死锁的可能解决方案是什么。

Many thanks 非常感谢

Answer 1

If you are setting session attributes from servlet(after login) then when you move to another JSP from it, the session will retain and you do not need to write 如果要从servlet设置会话属性（登录后），那么当从servlet转移到另一个JSP时，该会话将保留，并且您无需编写

<%@ page session="false" %>

on that JSP. 在那个JSP上。 All the attributes that you set will be available for you in the session. 您设置的所有属性在会话中将对您可用。

Here's a test code : index page shows 'name' attribute set in servlet - MaintainSession also when you press 'next JSP' button, it takes you to another new JSP which again shows the 'name' attribute. 这是一个测试代码：索引页面显示了servlet中设置的“名称”属性-当您按下“下一个JSP”按钮时，也会通过MaintenanceSession进入另一个新的JSP，它再次显示“名称”属性。

None of the JSP needs the <%@ page session="false" %>. JSP都不需要<％@页面session =“ false”％>。

index.jsp index.jsp

    <body>
        <form action="MaintainSession" method="post">
            <input type="submit" value="Set Session Attribs"/>
        </form>
        <h1>Name : ${sessionScope.name}</h1>
        <h1>Name : <%=session.getAttribute("name")%></h1>
        <form action="Next.jsp" method="post">
            <input type="submit" value="Next JSP"/>
        </form>
    </body>

Next.jsp Next.jsp

    <body>
        <h1>Hello World!</h1>
        <h1>Name : ${sessionScope.name}</h1>
        <h1>Name : <%=session.getAttribute("name")%></h1>
    </body>

MaintainSession.java MaintenanceSession.java

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
       HttpSession session = request.getSession(true);
        session.setAttribute("name", "MyName");
        request.getRequestDispatcher("index.jsp").forward(request, response);
    }

The flow : 流程：

index.jsp ----Press Set Session Attribs---> MaintainSession servlet ----> index.jsp ---- press Next JSP ----> Next.jsp

JSP：关于具有约束登录状态的系统中的会话

问题描述

1 个解决方案

解决方案1
1 已采纳 2014-07-07 12:45:57

JSP：关于具有约束登录状态的系统中的会话

问题描述

1 个解决方案

解决方案1 1 已采纳 2014-07-07 12:45:57

解决方案1
1 已采纳 2014-07-07 12:45:57