Now, I have one more metadata issue, its one that exists in maven-land
too; both need to address it. Maybe, just maybe, OSGi addresses it.
How do you stop competing XML parsers, XSL engines or stuff implemented
in javaee.jar from getting duplicated in a classpath?
Here is a bit of the httpunit dependencies, as inferred from m2:
jtidy by jtidy 4aug2000r7-dev integration maven2 false 135 kB
js by rhino 1.5R4.1 integration maven2 false 583 kB
nekohtml by nekohtml 0.9.1 integration maven2 false 66 kB
--- xerces by xerces 2.4.0 integration maven2 false 875 kB
xercesImpl by xerces 2.6.2 integration maven2 false 987 kB
xmlParserAPIs by xerces 2.2.1 integration maven2 false 81 kB
Two copies of Xerces, and a version of xmlParserAPIs that may or may not
match.
Ideally you'd want to know which JARs declared interfaces (each by a
unique name, or even a unique URL), and which JARs implemented them.
Then at least you could warn if there was a conflict. Deciding which
version is newer is trickier; the metadata would have to include version
information about the interfaces of an artifact:
<implements uri="http://jcp.org/233/dom"; version="3.0" />
so not only would a conflict between xerces and crimson show up, the
resolver would know not to use crimson.
-steve
