React

From APIDesign

React.js is one of the most popular UI framework these days. Backed by Facebook, it appeals to masses - it has almost become a synonym for UI in the browser/mobile - especially between managers with only high-level knowledge.

JSX

React comes with enhanced version of JavaScript called JSX which mixes the code with DOM definition. Many love it. Some consider it crazy. Anyway it is certainly a challenge to convert such concept to another language like Java and to do it without enhancing the language - only with the help of AnnotationProcessors.

Can that be done? Yes, it can. See my react4jdemo tutorial or go directly to the project page.

This Virtual DOM allows one to easily compose a hierarchical structure of elements and treat it as an object. Both in JSX as well as in Java.

What's Reactive on React Anyway?

The best way to learn about weaknesses of React is to watch rants by competitors. This one comes from Svelte: