How to exclude a dependency from parent's project in Maven?

Question

For example, I have 2 Maven projects. One is \"project-parent\". The other is \"project-child\". Obviously, \"project-child\" is the sub project of \"project-parent\".

Answer 1

One hacky way to accomplish this is to specify the dependency in project-child but with 'test' scope (or whatever lightest-weight scope is available). This will "hide" the scope specified in project-parent so that it is available only to test code, and unavailable to non-test code at both compile and runtime.

I came across this bug-feature mostly by mistake. In my case, my project-child had a project-sibling with a 'compile' scope dependency, while project-parent had the same dependency specified (actually inherited from a grandparent) with 'provided' scope. project-child was an executable however that depended on project-sibling, and so a NoClassDefFoundError was thrown at runtime from project-sibling since project-child's runtime classpath was being used, which didn't include the 'provided' dependency. I fixed this by moving the 'compile' dependency from project-sibling to project-parent so that the 'compile' would "hide" the 'provided'.