Are you doing enterprise development in Java? Then stop. Java is neat, Java blazed the way for non-trivial cross-platform bytecode-based software development. Many systems that are not specifically web-centric rely on Java these days. It’s been way more than a decade that countless programming languages have come to life that address the Java VM. Scripting-centric PLs such as Groovy or Beanshell or modern, ultra functional ones like Closure or Scala.
Most of these are either obscure, of little use in larger projects or so far into one paradigm that development teams often have a hard time getting productive with them. However, 10 years ago, at the tail-end of the JVM language hype, one language emerged and hit the ground running: Kotlin. Built by the Czech software devtool company Jetbrains, Kotlin was introduced with productivity in mind, from day one. Today it is the de facto replacement for Java, in an environment that relies on Java components to run.
Kotlins integration with existing Java libraries is trivial and the language itself is a true and full-fledged modern redo of Java, outfitted with all paradigms that have proven themselves in the last 2 decades, including true functional style. On top of that, nearly 3 years ago Google declared Kotlin a first-class citizen for Android development, with Android Studio offering full support for development with Kotlin.
Ergo: Doing Java? Go Kotlin. You won’t regret it.