If session exist or not

user_1420026 0
Viewed 41721

I am trying to write my first app on Google App Engine, I was trying to maintain a session, I created a login page on submit, it call to a servlet, servlet validates the user and create a new session using the following code.

void createSession(String Username) {
        getThreadLocalRequest().getSession(true).setAttribute("Username", Username);
    }

login page after calling the servlet redirects to some page i.e. abc.jsp, my abc.jsp page contains 

<body><%
        try {
            if (request.getSession(false) == null) {

            } else {
    %>
    Welcome to
    <%=session.getAttribute("Username")%>
    <%
        if (session.getAttribute("Username").equals("")) {
    %>
    <a href="login.jsp"><b>Login </b></a>
    <%
        } else {
    %>
    <a href="logout.jsp"><b>Logout</b></a>
    <%
        }
            }
        } catch (Exception e) {

        }
    %></body>

it works fine, but when I access abc.jsp without creating a session it is throwing an exception at this if (session.getAttribute("Username").equals("")) line, I dunno why kindly help me. I think it dont detect if session exists. but I have read so many threads like this It gave me this solution, I dunno what I am doing wrong.

google-app-engine session jsp java
4 Answers

It Worked For me. Try This

String userName;
    userName = (String)session.getAttribute("uname");   
if (session.getAttribute("userName").equals(""))
user_104279030
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