Wro4j (Web Resource Optimizer for Java) make it easier for Java web developers to use things like SCSS / LESS / CoffeeScript / UglifyJS in their projects, without using the gems / npms directly.
I couldn't find though how do I use it for the simple use case of watching some SCSS files
What is the quickest equivalent to
sass --watch /src:/css
In wro4j?
I assume it is related to change detection. If it is true, than there is a configuration property called "resourceWatcherUpdatePeriod" which is used to check periodically resources for change. The next release (1.4.9) will improve the behavior of resourceWatcher by watching for change lazily.