I have a project that has:
In my experience, the frontend maven plugin is far and away the best plugin for this type of build/deploy process. https://github.com/eirslett/frontend-maven-plugin . This is how i use it for Grunt but it supports Gulp just as well.
com.github.eirslett
frontend-maven-plugin
...
src/main/frontend
grunt build
grunt
generate-resources
build
One thing to be aware of it is will download node for the system it is being run on, so if you have a different OS on your build server, you'll need to make sure that is the version you have checked into version control, your local version (for me OSX) will have to be maintained local to your project.