epub-translator is an utility to translate EPub books.

• Utilize DeepL API (You need to register DeepL API plan)
• Leave the original text for reference, and insert the translated text below per paragraph

This project uses Quarkus, the Supersonic Subatomic Java Framework. If you want to learn more about Quarkus, please visit its website: https://quarkus.io/ .

• JDK 11
• GraalVM (If you want to build a native image directly)
• Docker or Podman (If you want to build a native image in a container)

The application can be built and executed directly from the source dir using

./gradlew build
java -jar build\quarkus-app\quarkus-run.jar --src my.epub

The application can be packaged using following command:

./gradlew quarkusBuild -Dquarkus.package.type=uber-jar

It produces the epub-translator-runner.jar file in the build directory.

place application.yml to <epub-translator working directory>/config/application.yml

ePubTranslator:
  deepL:
    apiEndpoint: https://api.deepl.com # If you subscribe free API plan, use "https://api-free.deepl.com" instead.
    apiKey: <put your api key here>
  language:
    source: en        # default source language
    destination: ja   # default destination language

uber-jar

java -jar epub-translator-runner.jar --src <path to source epub file> [--dst <path to destination epub file>] \
[--srcLang <source language>] [--dstLang <destination language>]

A database is kept of previous translations. This is especially useful if a translation fails during processing, to avoid spending credit on already translated content. It also makes it possible to incrementally translate a book using limited credits, by running the translation again later when more credits are available

The database is located at ~username/.epub-translator.

epub-translator can count the characters in the file using --count. This can be used to estimate the cost in DeepL credits before executing the translation.

If the translated epub is not readable by your e-reader, it may be fixable by Calibre. Calibre has an eBook conversion tool, and converting the output book from epub to epub tends to fix the problems.