Have you tried Kotlin? It's a less clunky Java. The syntax is IMHO Ruby-level charming (for an OO-first lang), but with types that are quite a bit stronger than Java. Java interop is quite smooth.
I always thought that DSLs were the one thing Ruby did better than the competition, but Kotlin's combination of receiver lambdas plus syntactic sugar for calling higher-order functions make it an even better language to write DSLs in.