Christian Stein

Invalid Automatic-Module-Names

Already over 600 modules were uploaded to Maven Central lately, containing invalid names!

TLDR: Run jar --describe-module --file ARTIFACT.jar to verify the selected module name adheres at least valid Java syntax before publishing.

Examples of invalid names

• org.apache.jena.jena-fuseki-core ❌ no - allowed
• org.drools.wb.enum.editor.api ❌ enum is a Java keyword
• org.kie.wb.common.default.editor.api ❌ default is a Java keyword
• org.neo4j.tooling.import ❌ import is a Java keyword
• org.talend.sdk.component.runtime..standalone ❌ no .. allowed

If you find your published library, or that of a friend, listed below suspicious modules, please correct the module name as soon as possible.

An invalid module name is even worse than no module name.

How to name a module?

This summary is copied over from module-names-for-java-se-9-jpms:

• Module names must be valid Java identifiers! I.e. no Java keywords, no dashes, no…
• Module names must be reverse-DNS, just like package names, e.g. org.joda.time.
• Modules are a group of packages. As such, the module name must be related to the package names.
• Module names are strongly recommended to be the same as the name of the super-package.
• Creating a module with a particular name takes ownership of that package name and everything beneath it.
• As the owner of that namespace, any sub-packages may be grouped into sub-modules as desired so long as no package is in two modules.

Make sure to also read the full blog at java-se-9-jpms-module-naming

Build tool improvements

• Jar ?
• Maven Archiver MSHARED-773
• Gradle “Core” 7752