android-studio3-test

After upgrading to Android Studio 3.0 we also must use the new android gradle plugin com.android.tools.build:gradle:3.0.0-alpha1 and we should be able to use the java-library gradle plugin (instead of the java plugin) for java-only modules.

But this does not work: see tag java-library-plugin

The problem was in the gradle version. Updading to version 4.0-milestone-2 fixed the issue changes

Working tag: java-library-plugin-OK

see also:

• Stackoverflow When using gradle 'java-library' the classes in the library cannot be referenced
• Gradle Forum