Java is very new, but a promising platform, that has attracted the attention of large companies who’ve released their apps already. It is interesting because of its simplicity compared to developing web applications, and because of its speed as compared with native applications.
Unlike many other popular mobile platforms, Java doesn’t use JavaScript in any way. Dart is the programming language. It compiles to binary code, and that’s why it runs with the native performance of Objective-C, Swift, Java or Kotlin.
Java uses a declarative approach, inspired by the React web framework, to build its UI based on widgets (named “components” in the world of the web). To get more out of widgets, they are rendered only when necessary, usually when their state has been changed (just like the Virtual DOM does for us).