Need Help with Making Minecraft Plugin Generator in Java

Hello. I don't know if I should be putting this in this discord, tell me if its wrong though. I want to make a java application using visual studio and https://marketplace.visualstudio.com/items?itemName=georgewfraser.vscode-javac
for generating spigot plugins by using text boxes and buttons and such. But I don't know how to generate java code from that. I have seen many programs that generate code for commandblocks like this, but I don't know how :/
It also doesn't have to be java in visual studio, it could be jframe and such using an java ide.
Anyways.. Lets say that I am someone that is using my program. I open the program, click file, new project, and then name it, enter the starting version, and the package names. And then, I click new command, and a new popup window appears. I then enter the commad name, and stuff, and then click add command. then lets say I double click the newly created command and then it opens up new popup window where I can add parts to the command for what the command actually does.
Hopefully that makes sense.