I want to use morphia for my data access, but I also want to try to use Scala for web content. Is it possible to mix and match Java and Scala files, or if i choose to use Java,
You can definitevelly use both java and scala since Play is a JVM framework, not a Java nor a Scala one.
So in controllers, you could have a ScalaApplication.scala and a JavaApplication.java if you wish.
And they are callable (redirectable, ...) from each other.