如何在jsp中保持变量不变？

Question

I have the following code snippet in jsp:

String Key=null;

if(request.getParameter("project")!=null) { 
        Key = request.getParameter("project").trim();
}

if (AM == null) {
        response.sendRedirect("../portal/login.jsp?from=index.jsp");
}

In here after redirection the variable Key is changed. How can I keep this variable unchanged after redirection?

Answer 1

You can use key in session parameters otherwise you can use like this

String Key=null;

    if(request.getParameter("project")!=null){ 
        Key=request.getParameter("project").trim();
     }

if (AM == null) {
        response.sendRedirect("../portal/login.jsp?from=index.jsp&project="+Key);
    }

Using key in session is better one.

Answer 2

You can't keep values in variables on every page redirection because WEB is stateless. so you need to use sessions

http://www.jsptut.com/sessions.jsp