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Re: classpath & too many jars

John C. Bollinger
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VisionSet wrote:
> I think I can get 2000 characters on the classpath but I easily exceed this
> with all the jars req'd for struts, jstl, hibernate, jdbc etc etc
> First I tried unzipping everything and putting everything in just 1 (or a
> few) jar. But this doesn't make updating versions easy, and is a big hassle
> anyway.
> Then I hear of the extension mechanism.
> Surely if I put everything in there then, when I distribute my app, those
> packages will no longer be available? It is obviously not the case with a
> webapp where I can distribute the JRE also. Or does the EM do special
> magic?
> What other options do I have?

It depends on what you are trying to do. If you are developing a webapp
then one of your options is to place all the required jars in
WEB-INF/lib -- then you don't have to explicitly specify them in the
classpath at all. Application servers also typically have directories
in which you can place jars that should be accessible to all webapps;
for general things like struts, etc. that might be a better choice than
using the JRE's extension directory. You always have the option of
writing a custom ClassLoader.

All in all, it seems like you have mostly a packaging problem. Some
approach this sort of issue by doing exactly as you first described, and
putting all the required classes in one jar. That doesn't make updating
easy for end-users, but gives you some control over the versions in use
(convenient if an update to one of the third-party packages could break
your app). Others require that users install the third-party packages
themselves, oftentimes in a prescribed way. Still others take the
ClassLoader route. Which you should choose depends on your specific needs.

John Bollinger Removed)

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Wendy S
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"VisionSet" <(E-Mail Removed)> wrote:

> Unit Testing ?!

JUnit tests work fine from Ant with an enormous list of .jar files listed in
the classpath within the build.xml file.

If you're building a webapp, Ant will save you a lot of time in building,
testing and deploying. I wouldn't want to begin to do this at the command
line, although it's certainly possible.

Wendy in Chandler, AZ

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