Comments on: @License(name = “Apache”,version = “2.0″) annotations and GPL

By: Alex Miller - Java 7 Roundup (November 3rd)

Alex Miller - Java 7 Roundup (November 3rd) — Sun, 04 Nov 2007 03:42:45 +0000

[...] And in some non-closure news, Stephan Schmidt had the idea of using a standard annotation for indicating licensing and/or copyright. I think it would be useful to have standard annotations for this as it would aid automatic checking and reporting of library licensing, which is something many organizations have to deal with. [...]

By: stephan

stephan — Sun, 28 Oct 2007 11:06:54 +0000

I guess the same for copyright would be a good idea. A container could know about licenses and issue a warning when injecting incompatible stuff. This would make some managers in companies happy.

By: Paul hammant

Paul hammant — Sat, 27 Oct 2007 21:24:19 +0000

that package-info.java thing would be a neat trick. Something similar could work for copyright. When coding pico2’s annotation support, I looked at directly supporting guice’s @inject. Theres some weirdness in respect of the classpath - getAnnotations() will alwaysvcome back with a result even if there were classdefs for annotations missing from the classpath. The resulting set of annoations for a member/etc would silently omit those for missing classdefs. Thus @license and @copyright could be added to jdk7 and sorta work for jars aimed at jdk5 as long as @since was ommitted for those new annotations.

Guice/pico and the new by-class-def side of Spring - almost certainly gpl entangled by virtue of import :-(
On a case by case basis of course.

By: stephan

stephan — Tue, 23 Oct 2007 21:25:05 +0000

“Except that’s not a java feature.” ? Package level annotations? I thought package level annotations can be done with package-info.java and @Target({ElementType.PACKAGE}) (My IDEA tells me that this is possible). So you could annotate licenses at the package level.

Yes, mixing licenses is possible, but needs a lot of attention to do it right. Radeox for example has a Apache 2.0 core and some BSD APIs.

And yes, XML might not be away around GPL. But it can be. But as with mixing licenses, this is a tricky question and there are different opinions.

And considering Guice: I’m not sure what using annotations, or annotating clases with your licensed annotations really means in the context of “linking”. Noone has thought that through I think.

By: Paul hammant

Paul hammant — Tue, 23 Oct 2007 20:37:09 +0000

the annotation would be good at package level I think. Except that’s not a java feature.

Also, it is possible to use GPL in a GPL-incompatible app provided it is done so through an API that is mutually compatible. Remember the MIT licensed SAX API? You still have to distribute source for the gpl bit, but the rest can be non-gpl. The creation of the api cannot be a gratuitous refactor of an existing library solely fir the purpose of getting out of a license situation. Sax was a weird API…

Lastly, guice (and picocontainer) are different to spring for the most part. The former do depend on imported classes. The latter prefers XML markup. XML markup ain’t a way round gpl rules though. At least not without reading the supporting notes to the gpl 100 times.