Play framework logging all RuntimeException in futures

Question

I'm creating application in Play Framework 2.2 using Scala, and I want to save in my log files all RuntimeException.

When I add to code something like:

future.map { f => throw new NullPointerException("bad things happen") }

I have any info in my logs. How should I configure my log4j, and why such behavior is by default?

=== Update

I can catch this exception inside, but maybe there is some better way of catching it outside:

future.map { f => try { ... throw new NullPointerException("bad things happen") } catch { case e:RuntimeException => ... } }

Answer 1

Instead of using try-catch you can call recover method of the future and print stack trace there:

future.map { f =>
    throw new NullPointerException("bad things happen")
}.recover { case ex => ex.printStackTrace() }