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Detecting Frame with JSP

Hi,

I am running a JSP Server with Tomcat 4.1
How can I detect a page if it is in a frame (or frameset).

This question should be easy if we using JavaScript code:

if (self != top)
alert('In a frame');
else
alert('Not in a frame');

but I need a pure JSP code, not javascript !

Please help, Thanks so much.

lhankins

You can use JS from JSP.

A JSP is implicitly compiled into a Servlet by the servlet container. A Servlet will service a request and return back an HTML response stream (which can include CSS, JS, etc).

So basically you have :

JSP -> Servlet -> HTML Document

mnphan

ASKER

Thanks lhankins,

You're right,

I even finish my JSP program in that way. It worked well except it turns out to another problem.

When I detect a page in a frame using a javascript and depending on this page if it is in a frame or not I then redirect it to another page, either frame.jsp or no_frame.jsp

if (self != top)
window.location.replace('/no_frame.jsp');
else
window.location.replace('/have_frame.jsp');

but when I redirect the page using JavaScript, I lost all the informations (error message, log-in status...) in that section.

I thought, it will be different if I can detect a page in a frame directly using JSP code and then using <jsp:forward page="no/have_frame.jsp"> which I still keep all information in that section.

mnphan

ASKER CERTIFIED SOLUTION

rrz

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mnphan

ASKER

Could you use session object ? ( session.setAttribute(String,Object); )
Yes. I using some thing like:
<jsp:useBean id = "id1" class="ErrorMsg" scope="session"/>
When I redirect a page using JavaScript window.location.replace('/no_frame.jsp'); I will lost all information in this session.

> window.location.replace('/no_frame.jsp?p1=1&p2=2');
It works but I really don't like this because p1 could be contain some values that I don't want to display to user via URL address.

mnphan

rrz

>When I redirect a page using JavaScript window.location.replace('/no_frame.jsp'); I will lost all information in this session.
Why is that ?
Did you use
sessionId=<%=session.getId()%>
to test ?

Oliver_Dornauf

mnphan - with pure jsp you can not "bust" a frame. It is _just_ a way how a browser displays you html page.

mnphan

ASKER

Thank you you all,
and sorry for this late post, as I was unable to post a message at home, I don't know why my PC couldn't see a text box where to type this message.

rrz, you're right again, when I redirected a page using JavaScript window.location.replace('/no_frame.jsp'); it does not lose any information in that session, every thing was still there, I was wrong because before redirect the page I did get those info and clear them.

My problem is now solved, I close this topic and give the credit for rrz, who pointed out my error.

Thanks all
PS. However, if some one has any idea to detect a frame using with pure JSP, please post. I still believe that JSP can do it without any help from other language !