Question

Is it possible to define a dependency in the pom such that it has the scope of system but points to multiple jars?

I’m sure this is quite unorthodox, however, I was just wondering whether this was even possible. So something like:

<dependency>
  <groupId>foo</groupId>
  <artifactId>foo</artifactId>
  <version>1.0</version>
  <scope>system</scope>
  <systemPath>${basedir}/lib/foo/*.jar</systemPath>
</dependency>

Answer 1

First (and I’ll never repeat it enough), using system scoped dependencies is discouraged unless you know exactly what you’re doing. From Dependency Scopes:

system: This dependency is required in some phase of your
project’s lifecycle, but is
system-specific. Use of this scope
is discouraged: This is considered an
“advanced” kind of feature and should
only be used when you truly understand
all the ramifications of its use,
which can be extremely hard if not
actually impossible to quantify.
This scope by definition renders your
build non-portable. It may be
necessary in certain edge cases. The
system scope includes the
<systemPath> element which points to
the physical location of this
dependency on the local machine. It is
thus used to refer to some artifact
expected to be present on the given
local machine an not in a repository;
and whose path may vary
machine-to-machine. The systemPath
element can refer to environment
variables in its path: ${JAVA_HOME}
for instance.

Now, to strictly answer your question, declaring a dependency with a system scope that would point on several jars is “possible” IF the dependency has a MANIFEST.MF listing other JARs relatively in its Class-Path entry. Something like this (assuming the “root” dependency is in lib):

Class-Path: ../lib/bar.jar ../lib/foo.jar

But I do NOT recommend this approach, especially in your particular case. Instead, have a look at this previous answer where I describe how to setup a file-based repository.