There are several of these… the most well-known being GWT (Google Web Toolkit). It’s been around quite a while, but I’ve heard it has its fair share of issues (Disclaimer: I’ve never used it myself).
There’s also JSweet which I’ve never used, but if I wanted to transpile Java to Javascript I would probably start there.
You will likely find the following thread interesting: Java vs JavaScript. Why not both? aka. Browser war again!