tomcat-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Konstantin Kolinko <>
Subject Re: Supporting more general globs in loader definition?
Date Thu, 23 Jun 2011 17:46:12 GMT
2011/6/23 Rainer Jung <>:
> At the moment the file globs we support in the loader definitions in
> are hard coded to DIRECTORY/*.jar.
> Sometimes it would be helpful to allow a bit more flexible globs, like
> e.g. log4j-1.2.*.jar or similar.
> Would there be any interest if I would investigate whether we can use
> e.g. the DirectoryScanner from ant to support more general globs?
> Since we want to define the loader path, we only want to end up with
> directories and jar files. So one idea would be to filter the result of
> the DirectoryScanner to only include dirs and jars that match. If we
> find that more secure, we could also restrict to jars only, because I
> think that's the most probable use case for globs and picking up any
> dirs e.g. when using a recursive pattern might not be what the user
> expected.
> The result should be compatible to what the users got when using the
> strict *.jar pattern.
> Since we scan the directories only on startup and the ant code is
> mature, I don't expect any problematic performance impact.
> I don't have a patch yet, but wanted to check for general feedback
> before investigating more deeply.
> Regards,
> Rainer

So, you are talking about common.loader, shared.loader, and
server.loader values in file.

(I somehow thought it was about jarsToSkip).

It is hard to find a use case for this feature you are asking for.

The only use case that comes to my mind is to prioritize some jars
over the others.
E.g. to put  ${catalina.base}/lib/patch-*.jar  ahead of the other
*.jars in the same directory. Though it does not differ much from
using ${catalina.base}/lib/patches/*.jar

So, technically I do not mind allowing any name prefix before *.jar. I
do not think there should be more wide glob support, like allowing '?'
or '*' in any position in the name. Do you have a use case for globs?

Politically, I do not like to have much emphasis on the
"common.loader" property.

I expect the list of jars to be put in "common.loader" to be rather
short. You put there the jars used by Tomcat, the jars used by
components declared in server.xml and context files, database drivers.

People should really put everything else into WEB-INF/lib,  or use a

As an example of a mess:  using the pattern "log4j-1.2.*.jar" from
your example  it is easy to select several versions of Log4J, which
might result in a disaster.  If there is only one version of log4j,
why not to copy or symlink it into designated directory? Thus all the
libraries will be in one place and will be easier managed.

One more note:
I recently added support for arbitrary system properties expansion in
the value of common.loader and other *.loader properties.  As a side
effect it is now possible to use whatever Unix command (e.g. find) in to build a list of jars and define it as a system property.

Summarizing: I do not mind to add support for name*.jar, but will
think twice about anything else.

Best regards,
Konstantin Kolinko

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message