Install vaadin and ... to test

Hi all,

I know very well Java (starting with java in 1997. I want develop tools on the web, so I am looking for framework like GWT, Vaadin, …
I use Eclipse, I don’t know JavaScript, and I don’t want become a devlopper with JS.

So I have some question:
which Eclipse I need to install (JEE, Javascript, …)?
I need or not install Spring tools (I don’t know Spring)?
It seems that the build need npm, I have install npm but maven build don’t found it?

I have yet install and used GWT easely, I start with vaadin and eclipse and after 24 hours i have still not run a start project!!!
Thanks a lot for your help.