The interaction can happen in both directions: Kotlin code calling Java code, and Java code calling Kotlin code. This is especially possible given the trend towards modularisation in the Android ecosystem, where modules are developed by multiple teams which, although they are working on the same product, are operating independently from each other, all the way down to choice of language. Since both Java and Kotlin can coexist on the same codebase, it is possible to have Kotlin and Java code coexisting for an undetermined period of time. The SDK developers might want to write the library in Kotlin to take full advantage of the language, but End Users may be integrating the SDK into an app written in Java.Īnother example is a single App with a diverse codebase. In Android, this is likely to happen frequently.Ī typical example is an SDK, whose API might be called from a variety of apps.

Interoperability rules are key when we are working on projects that will require both languages to interact with each other. The conversion is not always problem-free, but it generally does a good job.Ĭonverting from Java to Kotlin in IntelliJ-based IDEs. For instance, IntelliJ and Android Studio allow users to convert files from Java to Kotlin. Kotlin has been designed from the beginning to fully interoperate with Java, and both JetBrains and Google have pushed in that direction. It will likely help me as a journaling practice, and hopefully can help other potential readers that end up here trying to find some tips while they are facing the same problem.Īndroid developers are generally aware that Java can interact with Kotlin relatively seamlessly. I am currently working on a multi-module project that combines a variety of Java and Kotlin code, so I decided to publish my thought and notes as an article series. You can find the remaining article of the series here:įrom Java to Kotlin and back (II): Calling Kotlin from Javaįrom Java to Kotlin and back (III): Calling Java from Kotlin From Java to Kotlin and back (I) - Calling Kotlin from Java

Java to kotlin conversion online