Multi project builds - pford68/gradle-examples GitHub Wiki
A multi-project build is a build where you build more than one project during a single execution of Gradle. You have to declare the projects taking part in the multiproject build in the settings file.
Multi-project builds are always represented by a tree with a single root. Each element in the tree represents a project. A project has a path which denotes the position of the project in the multi-project build tree. In most cases the project path is consistent with the physical location of the project in the file system. However, this behavior is configurable.
The project tree is created in the settings.gradle file. By default it is assumed that the location of the settings file is also the location of the root project. But you can redefine the location of the root project in the settings file.
Hierarchical structure
include 'project1', 'project2:child', 'project3:child1'
The include method takes project paths as arguments. The project path is assumed to be equal to the relative physical file system path. For example, a path 'services:api' is mapped by default to a folder 'services/api' (relative from the project root). You only need to specify the leaves of the tree. This means that the inclusion of the path 'services:hotels:api' will result in creating 3 projects: 'services', 'services:hotels' and 'services:hotels:api'.
Flat structure
includeFlat 'project3', 'project4'
The includeFlat method takes directory names as an argument. These directories need to exist as siblings of the root project directory. The location of these directories are considered as child projects of the root project in the multi-project tree.