effiban / scala2java   6.3.0

Apache License 2.0 GitHub

A tool for translating Scala source code into readable and maintainable Java code

Scala versions: 2.13

Scala to Java Translation Tool


Scala is an advanced language built on top of the JVM, offering concise syntax and extensive support for functional programming. Unfortunately, although Scala has been around for quite a while (and is my personal favorite) - it hasn't gained the popularity that some expected, and is used today by only a small percentage of developers and applications (this is true for both the industry in general, and the JVM-based languages specifically).
At my company, we started out many years ago with a purely-Java codebase, and about 6-7 years ago began to introduce Scala. Over the years we accumulated a significant amount of Scala code in our microservices.
Recently, due to a lack of Scala expertise in the company and difficulty recruiting Scala developers, management decided to halt all Scala development and gradually replace existing code with Java. This presents a real challenge to us, since there is no straightforward way to do this without a lot of tedious manual work. Using a decompiler will of course produce equivalent Java code, but it is unreadable and unmaintainable.

Therefore, I decided to develop this tool - which is aimed at translating (transpiling) Scala code into readable and maintainable Java code, while adhering to the original style of the code (with certain limitations). Even though the generated code is not complete, I still believe it will save at least 80% of the manual work, that would otherwise be needed to carry out the translation.
I also hope it may prove useful to other companies/individuals as well.

Supported Language Versions

Tool: The tool itself is built with Scala 2.13 and Java 17.
Scala Input: The tool was tested with sources in Scala 2.13, and will probably work with earlier versions. There is no support for Scala 3.
Java Output: The generated files are in Java 17. In the future (if needed) other versions may be supported.

Maven Central Coordinates

Group: io.github.effiban
Artifact: scala2java-core_2.13

Usage Guide and Documentation

Refer to the Wiki


Scala2Java is licensed under the Apache License, Version 2.0.