Hi @drinkitup777, thank you for trying out my library and for your question. I have no experience with Java 9 modules so far but it seems that I have to add a module-info.java file to the library to make it work. This is mentioned in the Gradle docs. I will add this in the near future.

@pemistahl I'll be looking forward to it. I'm planning to use it for short text, so lingua is a perfect fit. Thanks for the fast reply.

The ModiTect plugin might be useful when implementing this for Lingua. It allows adding a module descriptor to an existing JAR. Its jvmVersion setting is also quite useful; it allows placing the module descriptor in a Multi-Release JAR directory (e.g. META-INF/versions/9) which avoids issues with Java runtimes and tooling < Java 9 which can be tripped up by the module-info.class file in the main directory. This should allow you to still support Java versions < Java 9.

(I have not tried the Gradle plugin yet, but for Gson its Maven variant is used, in case that is helpful).

@Marcono1234 I've tried your Gradle plugin but it seems it's not compatible with the Kotlin plugin. I get the following error:

Circular dependency between the following tasks:
:addDependenciesModuleInfo
+--- :generateModuleInfo
|    \--- :jar
|         +--- :classes
|         |    \--- :compileJava
|         |         \--- :addDependenciesModuleInfo (*)
|         \--- :inspectClassesForKotlinIC
|              \--- :classes (*)
\--- :jar (*)

Instead, I will create the file module-info.java manually and put it in src/main/resources/META-INF/versions/9. As far as I understand, the following content should be enough:

module com.github.pemistahl.lingua {
    exports com.github.pemistahl.lingua.api;
}

@drinkitup777 Are you perhaps able to test it before I release version 1.2.0? Thank you.

I get the following error:
...

Ah you are right, I am seeing the same error as well. Have reported it as moditect/moditect-gradle-plugin#14; but it appears there is a workaround.

Instead, I will create the file module-info.java manually and put it in src/main/resources/META-INF/versions/9. As far as I understand, the following content should be enough:

Should the api.io package be publicly exported as well? Since packages are not hierarchical the existing exports declaration is not enough.
It looks like the created JAR contains the module-info.java file in source form, instead of a module-info.class file. Additionally, for the file to be recognized from META-INF/versions/9 the MANIFEST.MF has to declare that the JAR is a Multi-Release JAR, otherwise the Java runtime does not consider any classes in these folders.

Have created #138 which tries to solve this using moditect-gradle-plugin.

This issue has been resolved by #138, so I close it now.

@drinkitup777 If you still have problems with the current solution, then please open a new issue. Thank you.