Here is a very nice trick I discovered almost by chance. Maven is an amazing tool to build software project. It scales...
Complex and big projects follows the SCM (Source Control Management) structure, usually a tree. Maven's best weapon is indeed to structure the project in a tree, where each node contains a pom that follows more or less the following rules:
- module list is the list of children,
- it shares definition with its subtree,
- its parent pom is the parent in the tree.
- its groupId is parent groupID plus parent artifactID
Indeed, this is smart.
However sometimes in the tree there are duplicates. A java-like project can occur at several places and then it becomes impossible to share, except at the closest common parent.
Fortunately, there is a trick that uses a quite original feature: pom can refer to any arbitrary parent pom. The idea is then to keep separated a hierarchy of pom. These are very specialized and inherits all from a root pom.
Now we keep the project tree, but when needed a pom can break the parent rule and refers to one of these poms instead of the tree parent. Different subtrees of same kind can now share the same parent pom.