Hi fellow Servletters/JRunners!
The problem in short:
After upgrading from JRun 2.X to JRun 3.0(SP1 does not help) Netscape
browsers randomly print the content of the stylesheet.css file we have
externally linked instead of printing the HTML. But if I do a "View Frame
Source", I see the HTML it is supposed to print. The stylesheet is linked
this way (in a correct place in the <HEAD> part of the document):
<link rel='stylesheet' type='text/css' href='/SD/Stylesheets/Stylesheet.css'
>
I have spent several days with this issue, but have not found a satisfactory
solution yet. But I have nailed the problem down, and come up with a few
workarounds (described later).
Server Info:
I run JRun 3.0SP1 (With a web application named SD, consisting of pure
servlets), NT4SP6a Server, Netscape 4.75 (all Netscape 4.X browsers I have
tested have the problem).
The source of the problem is that Netscape is very sensitive of the
format/content of the response the web server delivers when Netscape is
loading external linked stylesheets, with this type of link:
<link rel='stylesheet' type='text/css' href='/SD/Stylesheets/Stylesheet.css'
>
With JRun 2.X, this was no problem, since it only served the files that was
requested with /servlet/ somewhere in the URL, IIS served the static content
(images, .js, .css).
This has changed in JRun 3.0. IIS now hands over ALL requests that include a
JRun web application name to JRun. Meaning that all requests that contain
/SD/ (in my case) will now be handled by JRun. JRun uses a special servlet,
allaire.jrun.file.FileServlet, to serve static content (None of this is
confirmed by Allaire, but my "reasearch" indicates this).
This is the root of the problem. The FileServlet seems to fail to format the
response to the request for .css files perfectly, so Netscape messes up and
prints the contents of the .css file instead of the HTML (formated by the
linked .css file). But as an additional complexity, this does not happen
consistently. The frequency varies, and one of our servers with Win2000,
JRun 3.0 (Not SP1) and IIS 5.0 has no problems. While other Win2000, JRun3.0
servers HAVE the problem.
What I have tried with failure:
* I have searched the Internet thouroughly, and I found one other person
(Phil Callister) with the same problem. ONE! I discussed it with him on
email, he had not found any "real" solution, just a workaround (I also found
this workaround, it is described later in this email). But that is
disturbing, I suspect that JRun 3.0 has a major flaw in it's handling of
.css files and NO ONE else has the problem? It turns out that the use of
external .css files seems to be rare (at least I could not find many
examples of it out there!). I believe that is why so few others experience
this, because JRun 3.0 HAS a flaw with handling .css files, I am 99% sure.
* I have spent hours trying to change the MIME type - file extension
mappings in JRun (and also in Netscape), but nothing helped. .css <->
"text/css" is not registered in the properties files in JRun, so I added it
to both global.properties and local.properites for SD. No good. I used the
admin tool for the SD app, added it there, no good. I manually modified the
Registry on my Win NT 4.0SP6 server, addedd the mapping every thinkable
place, no good.
* I created a servlet, CSSWriter, that writes the content of a .css file
(after reading it from disk) to the response, ensuring that
response.setContentType("text/css") is called. The I linked to this servlet
instead of Stylesheet.css. No good. I modified it, by manually examining the
response IIS sends when you request a .css file from it, so that my servlet
sent an EXACTLY similar response (with correct ContentLenght and a few other
"cannot-be-important" headers in addition to the ContentType).
What I have tried with success:
A) Create a virtual directory in IIS, named something else than my JRun app,
for example SDStyle. In this virtual directory I placed the Stylesheet.css
file. Then I changed my links, to this:
<link rel='stylesheet' type='text/css' href='/SDStyle/Stylesheet.css' >
JRun does not have an application named "SDStyle", so IIS serves the file.
And it works. The problem is gone. This was the solution the other gentleman
(Phil Callister) had also found (and used now, for several months, I
believe).
B) Stop using externally linked .css files and use <STYLE type="text/css">
</STYLE> tags instead. This is interesting:
One of the other developers here showed me that the JRun 3.0 Admin web site
uses externally linked stylesheets. I checked it with IE (the HTML source),
and sure, they do. I tried the admin tools in Netscape and they were fine.
No problems. BUT THEN I checked their HTML source in Netscape, they do not
use externally linked stylesheets if the browser is Netscape, they use the
"inline" version, with <STYLE type="text/css"> <STYLE> tags.
So it seems they have found a problem and used a quick workaround.
There are two major drawbacks to this method for us:
1. A much larger amount of data will be transferred from the server to the
client, since the style information now is sent everytime, instead of being
linked once and then cached in the browser.
2. We have to rewrite all our HTML pages (several hundreds).
Anyone else having this problem? Any solutions? Allaire people, any
information you can share with us? Is this a bug?
~ Tormod
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Tormod Hystad
Senior Developer, R&D
CatalystOne Inc.
email: [EMAIL PROTECTED]
web: http://www.catalystone.com
phone: +47 93 09 60 81 (Norway)
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