HELP: JSP + XML + XSLT = HTML?

Question

Hello, all.
I am trying out Weblogic 6 and I am trying to get the JSP + XML + XSLT =>
HTML chain working.
I am coming from using Orion and SAXON.. and in that situation I had a JSP
that contained XML tags... they were filled in at runtime and then using
Servlet-Chaining was passed along to the SAXON XSLT Processer. SAXON checked
for the inline XSL specified and then used that to transform the document
into HTML.
It worked well, but there were some other features missing/not documented
that we now need.
With Weblogic I am trying to use the XSLT Tag Library that comes with the
distribution, but it seems to be very finicky. I followed the directions and
I got it to do a sort of roundabout transformation. But it doesn't seem to
work quite right.
The best I can get is the following:
I have an 'xslt' directory url-pattern-mapped to xslt.jsp (as instructed)...
but can't figure out how to specify the xsl file on-the-fly... that is, if I
don't hard-code the XSL file in the x:xslt element in the xslt.jsp it
complains about some XML file not having a root element.
Ideal situation:
1. I have a JSP that includes XML elements.
2. It is filled from a database at runtime and specifys (using a PI) what
XSL stylesheet it is to be processed with.
3. Somehow (fingers crossed) the XML is processed and transformed into HTML
by the appropriate XSL file.
I think I am mostly stuck moving between steps 2 and 3.
Can anyone give me some hints? Are there some Weblogic specific
elements/tags that I have to include in the XML file that Weblogic will
catch and re-direct to the XSL Parser?
Please, anyone, if you have some information, I would much appreciate it.
Dylan Parker
PS - I apologize for the cross-post, I hope it doesn't cause too much
traffic.

Answer 1

Craig,
I've since discovered how to do it with the WL Taglibrary... and have
moved on =)
It has to do with the EXTREMELY BADLY documented x:xml tag that can
appear within the x:xslt tag body...
So the WL Tag Library allows something like the following.
(Please note, angled brackets are omitted in this post to prevent html
parsing)
[x:xslt stylesheet="sheet.xsl"]
[x:xml]
Here is the XML to run the sheet on.
This should have all relevant XML syntax: the PIs, the doctype,
root elements etc...
[x:xml]
[x:xslt]
And that DOES work. But not very well. WL, a little prematurely
incorporated versions 1.2 of Xerces and Xalan in their product -- and
these versions have some irritating bugs.
Also -- There tag library doesn't copy the source XML across as UTF-8
.. so a lot of the Japanese I have embedded there (from a DB) gets
mangled somewhere in their code...
AND -- If you hammer a little bit on an JSP/XML that uses the WL Tag
Library (eg clicking refresh lots of times in IE)... I get huge
amounts of irritating exceptions appearing in the log files.
NullPointerExceptions
XSL Parsing Exceptions
XML Parsing Exceptions
but completely unpredictably...
In my eyes.. the WL XML/XSL Tag Library using the incorporated and
untouchable Xalan and Xerces (v1.2) is virtually unusable.
What a pain.
BUT! Apache offers a similar OPEN SOURCE XSL Tag Library available
here:
http://jakarta.apache.org/taglibs/doc/xsl-doc/intro.html
And it uses the standard, non-weblogic-incorporated, Xerces and Xalan
(which means you can provide whatever version you want).. and it works
impressively well.
It has almost identical performance as the WL Taglib, and without all
of the bizarre exceptions being thrown.
And it does proper passing of the character encoding type!
If only the taglib did caching though =(
The performance hit over pure JSP is huge. Almost two orders of
magnitude. On my desktop box I can get around 500Requests/Sec if I am
returning HTML direct from a JSP... while if I produce XML that gets
processed by XSL into HTML the Requests/Sec drops to 5!!!!
Caching. Caching. And more Caching. A lot of DiskIO is going on with
the XML/XSL/XHTML chain of events.
I hope this helps!
I'd be curious as to what you find out as well.
Dylan Parker
On 5 Mar 2001 07:20:00 -0800, "Craig Macha"
<[email protected]> wrote:
>
Yep, I feel Dylan's pain.
I am trying to accomplish the same thing. A JSP page generating
dynamic XML content and then utilizing an XSLT stylesheet to transform
all the content into XHTML.
Does anyone have some examples that show exactly how to accomplish
this? Can I do this with WLS and the XML taglib that comes with
it? Or do I have to move on to something like Cocoon to get this
capability?
Any insight would be greatly appreciated.
Thanks,
Craig Macha
"Dylan Parker" <[email protected]> wrote:
Hello, all.
I am trying out Weblogic 6 and I am trying to get the
JSP + XML + XSLT =>
HTML chain working.
I am coming from using Orion and SAXON.. and in that situation
I had a JSP
that contained XML tags... they were filled in at runtime
and then using
Servlet-Chaining was passed along to the SAXON XSLT Processer.
SAXON checked
for the inline XSL specified and then used that to transform
the document
into HTML.
It worked well, but there were some other features missing/not
documented
that we now need.
With Weblogic I am trying to use the XSLT Tag Library
that comes with the
distribution, but it seems to be very finicky. I followed
the directions and
I got it to do a sort of roundabout transformation. But
it doesn't seem to
work quite right.
The best I can get is the following:
I have an 'xslt' directory url-pattern-mapped to xslt.jsp
(as instructed)...
but can't figure out how to specify the xsl file on-the-fly...
that is, if I
don't hard-code the XSL file in the x:xslt element in
the xslt.jsp it
complains about some XML file not having a root element.
Ideal situation:
1. I have a JSP that includes XML elements.
2. It is filled from a database at runtime and specifys
(using a PI) what
XSL stylesheet it is to be processed with.
3. Somehow (fingers crossed) the XML is processed and
transformed into HTML
by the appropriate XSL file.
I think I am mostly stuck moving between steps 2 and 3.
Can anyone give me some hints? Are there some Weblogic
specific
elements/tags that I have to include in the XML file that
Weblogic will
catch and re-direct to the XSL Parser?
Please, anyone, if you have some information, I would
much appreciate it.
Dylan Parker
PS - I apologize for the cross-post, I hope it doesn't
cause too much
traffic.