I ran into this problem last week when I tried to write the Assets class as a Java class. I could solve the compilation problem by writing the Assets class in my submodule as a Scala class, as described in the docs: http://www.playframework.com/documentation/2.1.1/SBTSubProjects
Basically, my project structure:
MyApplication | - app | - conf | - modules | - admin | - app | - controllers | - admin | - Assets.scala | - project | - public
Contents of Assets.scala :
package controllers.contabil object Assets extends controllers.AssetsBuilder
And finally, the contents of my admin.routes file:
GET /assets/*file controllers.admin.Assets.at(path="/public", file)
Greetings
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