I've been trying to figure out how to get code coverage of the unit & integration tests. The tests are mostly written in Scala (there's a few java unit tests) and the application is written mostly in Java (there's a few Scala files).
I tried Clover, but (at this time) it doesn't support scala.
I tried Jacoco. First I ran into problems getting any results due to the mutli-module configuration of the project, but now using Sonar I've got the java coverage shown (thanks to http://www.aheritier.net/maven-failsafe-sonar-and-jacoco-are-in-a-boat/). I used timezra (http://timezra.blogspot.com/2013/10/jacoco-and-scala.html) with jacoco, but that only analyzed the small bit of source code that is in Scala.
I tried Scoverage, but that also has the same problem as timezra (it analyzes scala-to-scala, but not the mix that I have).