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how to keep some variable in different Jsp Pages  RSS feed

 
Ranch Hand
Posts: 62
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I user session to keep some variable in order to be used
in later different page.
when I use relative url to indirect another page, the session
become null.
for ex:
the A.jsp
<%
String userID = "aaa";
session.setAttribute("username", userID);
String myuserID = (String)session.getValue("username");
%>
User ID: <%=myuserID%><br>
UserJenny ID: <%=userID%><br>
<!--a href="testSessionB.jsp">All </a-->
<jsp:forward page="testSessionB.jsp"/>

the B.jsp
<%
String userID = (String)session.getValue("username");
%>
SessionUser ID: <%=userID%>

in A.jsp when I use
<a href="testSessionB.jsp">All </a>
the SessionUserID is null.
when I use
<jsp:forward page="testSessionB.jsp"/>
the SessionUserID is aaa.
So, what's the differents? and how can I keep my
variable for all the application?
Thanks
Krussi
 
Greenhorn
Posts: 24
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Hey Krussi,
maybe it's the easy way, if you implement a JavaBean in your page. You write and compile a JavaBean with the usual set and get methods to store your variables in it.
Then you set the Bean's scope to "session".
Here a code example:

To access the values in your JSP-Code, do something like this:

I think you should try it.
Greetings
H.-Gerd
 
Author and ninkuma
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I just tried your code on my Tomcat 3.1 server and it worked fine. One note: I'd suggest using getAttribute() instead of getValue() in your b.jsp
bear
 
krussi rong
Ranch Hand
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thanks everybody!
I want to use session keep some variables.
but the problem is when I use the local tomcat
the top code works fine, when I use the server's
tomcat,it didn't work. Is there anything to
do with the tomcat's configration?
thanks
Krussi
 
Ranch Hand
Posts: 1873
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hi,
i guess that is some server problem as session means it has to be same for the entire user session regardless of pages he/she visits...
of course JavaBean use is the best i would suggest as i do the same everytime to do session logout/login management for the users...its an elegant way i guess to just have a session level bean storing username/passwd and thats it! u r done.
regards
maulin.
 
It is sorta covered in the JavaRanch Style Guide.
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