Multi Project Build Help

I am fairly new to gradle and I was hoping for some guidance on the best approach. I have an application that consists of 4 different projects. Project 1, Project 2, and Project 3 are used for the server side code. Project 2 is compiled into a WAR file and it references Project 1 and Project 3.
The client side code consist of Project 3 and and Project 4. Project 3 references Project 4 and both of those projects produce a jar file.

What is the best way to build these? Thanks in advance for the help.