An attempt to convert Kotlin Lingua to Java Lingua

[azagniotov]

Context

@pemistahl Peter,

After coming across the:

• Replace native implementation with Java bindings to WASM module #214 and the Rewrite Lingua in Java #188

I decided to give it a go and lend a hand, or two. I do realize that without knowing your own progress with the #214, my effort may be a futile effort. But, I still decided to jump in.

I understand that you may be busy with real life and a young family, so whenever you have some feedback, I will really appreciate it. At this point, I would like to ask you how is it looking so far. Also, please let me know if you have any concerns. In any way, should there be any issues where I should not proceed further, I am happy to close the PR.

Thank you.

The State of Things

What has been migrated/achieved

• build.gradle has been migrated in order to build the project and run the tests
• The commits on the PR are atomic enough, so I hope this will enable you to review this with more ease.
• All the migrated test cases pass (apart from what has been outlined in Concerns so far below)
• Gradle plugin 'com.github.sherter.google-java-format' was added to help with formatting, e.g.: ./gradlew googleJavaFormat

What has not been migrated/achieved

• build.gradle artifact packaging, reporting and publishing still need to be tested out
• api package: LanguageDetector and LanguageDetectorBuilder, plus their respective tests
• accuracyReport package classes
• internal.io package classes

Concerns so far

• The test TrainingDataLanguageModelTest.assertThatUnigramLanguageModelIsCorrectlySerializedToJson is failing because the obtained JSON object keys are not in the same order as the expected JSON. Therefore JSON object string comparison fails.