Sometimes I just need to remind myself how crappy some Java APIs are...

gistfile1.txt

scala> import java.util.Properties
import java.util.Properties

scala> val defaults = new Properties
defaults: java.util.Properties = {}

scala> defaults.setProperty("test", "foo")
res8: java.lang.Object = null

scala> defaults.containsKey("test")
res9: Boolean = true

scala> val test = new Properties(defaults)
test: java.util.Properties = {}

scala> test.containsKey("test")
res10: Boolean = false

scala> test.getProperty("test")
res11: java.lang.String = foo

wat?

what tixxit said.

Use java.util.Properties! You'll have hours and hours of fun chasing bugs!