GUI development setup steps

[source-ram]

Hi,

I am a GUI developer and just started learning Java, i need to see if i can try to solve some GUI feature implementation like auto scroll, scroll bar, go to line/start/end, ..etc. Can any one give a hint from java backend side how can i keep the backend running and develop the front end part alone ?
I read few other discussion, where ng build -watch is used to build on the change, but i am not able to figure out the java side how to run the backend to use this build location ?

Appreciate any steps or hints