Java2Script provides an Eclipse Java to JavaScript transpiler (source-to-source compiler) and a nearly complete JavaScript implementation of the Java runtime environment (including AWT and Swing).
Java2Script is an integrated development system that allows interactive Java-to-JavaScript conversion within Eclipse, with immediate JavaScript testing and debugging in a browser, based on code developed in Java.
After installing the Java2Script Eclipse plug-in (“drop-in”), Eclipse creates
both Java .class files and their equivalent .js files simultaneously.
Together with a included JavaScript version of the Java Runtime Environment (JRE)
this allows the rapid and automated production of browser-ready JavaScript
versions of Java applications and applets.