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Posted to users@tomcat.apache.org by Tim Moore <tm...@blackboard.com> on 2002/10/04 00:11:16 UTC
Shared JSP taglibs
>From the JavaServer Pages 1.2 Specification:
JSP.7.3.5 Implicit Map entries from the Container
The container may also add additional entries to the taglib map. As in
the previous
case, the entries are only added for URIs that are not present in the
map. Conceptually
the entries correspond to TLD describing these tag libraries.
These implicit map entries correspond to libraries that are known to the
container, who is responsible for providing their implementation, either
through
tag handlers, or via the mechanism described in Section JSP.7.3.9.
Does Tomcat 4.1.x support this in any way? If so, can I add my own
taglibs to the map of known taglibs? We have several webapps running on
the same server that use the same tag libraries. Currently, we have the
tag handler classes in a shared JAR, and copy the TLD files into each
webapp. If I could avoid having to do the latter, that would be nice.
:-) I haven't seen anything to indicate that it's possible, but if it
is, that would be cool!
--
Tim Moore / Blackboard Inc. / Software Engineer
1899 L Street, NW / 5th Floor / Washington, DC 20036
Phone 202-463-4860 ext. 258 / Fax 202-463-4863
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Re: Shared JSP taglibs
Posted by Nikola Milutinovic <Ni...@ev.co.yu>.
Craig R. McClanahan wrote:
>
> In my experience, the (small) memory savings of putting classes into
> /shared/lib (or /common/lib) is not worth the hassles it brings:
What about building a "server-wide environment"? Suppose you have a set of Tag
Libraries that you either trust or wish to enforce on your server. Then it would
make sense to place them "server-wide". Of course, there are reasons against
such a strategy.
> - All the webapps running in this Tomcat installation must
> share the same version of the tag library (or whatever -- it's
> not just limited to these), so you have to upgrade them all
> together in lockstep.
Perhaps not such a bad idea. Of course, this puts an additional strain on the
administartor.
> - If your shared library wants to access application-specific classes
> that are only available in /WEB-INF/classes or /WEB-INF/lib, you
> have to program them specifically to access those classes via the
> thread context class loader.
True. Could Tomcat in some distant future release have a setup option in
server.xml on which global/local classes to use. It may be too much to ask. And
it is definitely a road to chaos.
> - You are depending on a non-portable feature of Tomcat (no concept
> of shared library directories is required by any of the Java specs;
> although most servers offer something like it, they are all
> implemented differently).
Yup.
Nix.
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Re: Shared JSP taglibs
Posted by "Craig R. McClanahan" <cr...@apache.org>.
On Fri, 4 Oct 2002, shanmugampl wrote:
> Date: Fri, 04 Oct 2002 09:46:32 +0530
> From: shanmugampl <sh...@india.adventnet.com>
> Reply-To: Tomcat Users List <to...@jakarta.apache.org>,
> shanmugampl@india.adventnet.com
> To: Tomcat Users List <to...@jakarta.apache.org>
> Subject: Re: Shared JSP taglibs
>
> I dont think that this solution will solve the problem. It says that
> instead of copying the tld files, make them as a jar and put it in the
> WEB-INF/lib directory. Still i will have to duplicate the tld files
> which is not desired.
I don't have this problem -- but maybe it is because of the way that I
have my development environment organized.
I separate the build process such that each tag library is built
separately - and the output is a JAR file which includes the TLD. Now,
whenever I want to use this tag library in a webapp, all I need to do is
grab that JAR file and drop it into /WEB-INF/lib.
> I have this same problem. What i want to know is
> that, like having the classes in shared jar(<Tomcat home>/shared/lib/),
> can i move my tld files outside my webapp and have it at a single place
> and access it across my contexts
>
In my experience, the (small) memory savings of putting classes into
/shared/lib (or /common/lib) is not worth the hassles it brings:
- All the webapps running in this Tomcat installation must
share the same version of the tag library (or whatever -- it's
not just limited to these), so you have to upgrade them all
together in lockstep.
- If your shared library wants to access application-specific classes
that are only available in /WEB-INF/classes or /WEB-INF/lib, you
have to program them specifically to access those classes via the
thread context class loader.
- You are depending on a non-portable feature of Tomcat (no concept
of shared library directories is required by any of the Java specs;
although most servers offer something like it, they are all
implemented differently).
My advice would be to make your webapps as self-contained and
independently replaceable as possible. Sharing classes across webapps is
not the way to do this.
> shan
Craig
>
> Craig R. McClanahan wrote:
>
> >Tomcat 4.1 doesn't have any "known to the container" mechanisms built in,
> >but there is a strategy you can use (also portable) to avoid having to
> >separately copy TLDs into your webapps. You can put TLD files in the
> >"META-INF/tlds" directory of a JAR file in /WEB-INF/lib (presumably the
> >JAR containing your tag library implementation classes), and Tomcat will
> >automatically recognize it. In fact, if your pages use the same URI that
> >you specify in the <uri> element in the TLD, you don't need to declare
> >them in the web.xml file either.
> >
> >Now, using a tag library is simply a matter of dropping a JAR file into
> >/WEB-INF/lib.
> >
> >Craig
> >
> >
> >
> >On Thu, 3 Oct 2002, Tim Moore wrote:
> >
> >
> >
> >>Date: Thu, 3 Oct 2002 18:11:16 -0400
> >>From: Tim Moore <tm...@blackboard.com>
> >>Reply-To: Tomcat Users List <to...@jakarta.apache.org>
> >>To: tomcat-user@jakarta.apache.org
> >>Subject: Shared JSP taglibs
> >>
> >>>>From the JavaServer Pages 1.2 Specification:
> >>
> >>JSP.7.3.5 Implicit Map entries from the Container
> >>The container may also add additional entries to the taglib map. As in
> >>the previous
> >>case, the entries are only added for URIs that are not present in the
> >>map. Conceptually
> >>the entries correspond to TLD describing these tag libraries.
> >>These implicit map entries correspond to libraries that are known to the
> >>container, who is responsible for providing their implementation, either
> >>through
> >>tag handlers, or via the mechanism described in Section JSP.7.3.9.
> >>
> >>Does Tomcat 4.1.x support this in any way? If so, can I add my own
> >>taglibs to the map of known taglibs? We have several webapps running on
> >>the same server that use the same tag libraries. Currently, we have the
> >>tag handler classes in a shared JAR, and copy the TLD files into each
> >>webapp. If I could avoid having to do the latter, that would be nice.
> >>:-) I haven't seen anything to indicate that it's possible, but if it
> >>is, that would be cool!
> >>--
> >>Tim Moore / Blackboard Inc. / Software Engineer
> >>1899 L Street, NW / 5th Floor / Washington, DC 20036
> >>Phone 202-463-4860 ext. 258 / Fax 202-463-4863
> >>
> >>
> >>--
> >>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
> >>For additional commands, e-mail: <ma...@jakarta.apache.org>
> >>
> >>
> >>
> >>
> >
> >
> >--
> >To unsubscribe, e-mail: <ma...@jakarta.apache.org>
> >For additional commands, e-mail: <ma...@jakarta.apache.org>
> >
> >
> >
>
>
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Re: Shared JSP taglibs
Posted by shanmugampl <sh...@india.adventnet.com>.
I dont think that this solution will solve the problem. It says that
instead of copying the tld files, make them as a jar and put it in the
WEB-INF/lib directory. Still i will have to duplicate the tld files
which is not desired. I have this same problem. What i want to know is
that, like having the classes in shared jar(<Tomcat home>/shared/lib/),
can i move my tld files outside my webapp and have it at a single place
and access it across my contexts
shan
Craig R. McClanahan wrote:
>Tomcat 4.1 doesn't have any "known to the container" mechanisms built in,
>but there is a strategy you can use (also portable) to avoid having to
>separately copy TLDs into your webapps. You can put TLD files in the
>"META-INF/tlds" directory of a JAR file in /WEB-INF/lib (presumably the
>JAR containing your tag library implementation classes), and Tomcat will
>automatically recognize it. In fact, if your pages use the same URI that
>you specify in the <uri> element in the TLD, you don't need to declare
>them in the web.xml file either.
>
>Now, using a tag library is simply a matter of dropping a JAR file into
>/WEB-INF/lib.
>
>Craig
>
>
>
>On Thu, 3 Oct 2002, Tim Moore wrote:
>
>
>
>>Date: Thu, 3 Oct 2002 18:11:16 -0400
>>From: Tim Moore <tm...@blackboard.com>
>>Reply-To: Tomcat Users List <to...@jakarta.apache.org>
>>To: tomcat-user@jakarta.apache.org
>>Subject: Shared JSP taglibs
>>
>>>>From the JavaServer Pages 1.2 Specification:
>>
>>JSP.7.3.5 Implicit Map entries from the Container
>>The container may also add additional entries to the taglib map. As in
>>the previous
>>case, the entries are only added for URIs that are not present in the
>>map. Conceptually
>>the entries correspond to TLD describing these tag libraries.
>>These implicit map entries correspond to libraries that are known to the
>>container, who is responsible for providing their implementation, either
>>through
>>tag handlers, or via the mechanism described in Section JSP.7.3.9.
>>
>>Does Tomcat 4.1.x support this in any way? If so, can I add my own
>>taglibs to the map of known taglibs? We have several webapps running on
>>the same server that use the same tag libraries. Currently, we have the
>>tag handler classes in a shared JAR, and copy the TLD files into each
>>webapp. If I could avoid having to do the latter, that would be nice.
>>:-) I haven't seen anything to indicate that it's possible, but if it
>>is, that would be cool!
>>--
>>Tim Moore / Blackboard Inc. / Software Engineer
>>1899 L Street, NW / 5th Floor / Washington, DC 20036
>>Phone 202-463-4860 ext. 258 / Fax 202-463-4863
>>
>>
>>--
>>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
>>For additional commands, e-mail: <ma...@jakarta.apache.org>
>>
>>
>>
>>
>
>
>--
>To unsubscribe, e-mail: <ma...@jakarta.apache.org>
>For additional commands, e-mail: <ma...@jakarta.apache.org>
>
>
>
Re: Shared JSP taglibs
Posted by "Craig R. McClanahan" <cr...@apache.org>.
Tomcat 4.1 doesn't have any "known to the container" mechanisms built in,
but there is a strategy you can use (also portable) to avoid having to
separately copy TLDs into your webapps. You can put TLD files in the
"META-INF/tlds" directory of a JAR file in /WEB-INF/lib (presumably the
JAR containing your tag library implementation classes), and Tomcat will
automatically recognize it. In fact, if your pages use the same URI that
you specify in the <uri> element in the TLD, you don't need to declare
them in the web.xml file either.
Now, using a tag library is simply a matter of dropping a JAR file into
/WEB-INF/lib.
Craig
On Thu, 3 Oct 2002, Tim Moore wrote:
> Date: Thu, 3 Oct 2002 18:11:16 -0400
> From: Tim Moore <tm...@blackboard.com>
> Reply-To: Tomcat Users List <to...@jakarta.apache.org>
> To: tomcat-user@jakarta.apache.org
> Subject: Shared JSP taglibs
>
> >From the JavaServer Pages 1.2 Specification:
>
> JSP.7.3.5 Implicit Map entries from the Container
> The container may also add additional entries to the taglib map. As in
> the previous
> case, the entries are only added for URIs that are not present in the
> map. Conceptually
> the entries correspond to TLD describing these tag libraries.
> These implicit map entries correspond to libraries that are known to the
> container, who is responsible for providing their implementation, either
> through
> tag handlers, or via the mechanism described in Section JSP.7.3.9.
>
> Does Tomcat 4.1.x support this in any way? If so, can I add my own
> taglibs to the map of known taglibs? We have several webapps running on
> the same server that use the same tag libraries. Currently, we have the
> tag handler classes in a shared JAR, and copy the TLD files into each
> webapp. If I could avoid having to do the latter, that would be nice.
> :-) I haven't seen anything to indicate that it's possible, but if it
> is, that would be cool!
> --
> Tim Moore / Blackboard Inc. / Software Engineer
> 1899 L Street, NW / 5th Floor / Washington, DC 20036
> Phone 202-463-4860 ext. 258 / Fax 202-463-4863
>
>
> --
> To unsubscribe, e-mail: <ma...@jakarta.apache.org>
> For additional commands, e-mail: <ma...@jakarta.apache.org>
>
>
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