Frontend Java Development in 2025

I couldn't make this work with JDK 23, 21 or 17, I got the following error:

Failed to execute goal org.teavm:teavm-maven-plugin:0.6.1:compile (web-client) on project flavour: Unexpected error occurred: Unsupported class file major version 61

According to the Docs it seems it seems to only work with JDK 8: (https://frequal.com/Flavour/book.html#org1b5c5fc):

17.1 Prerequisties Making web apps with Flavour only requires two prerequisites:

Java (OpenJDK 8 or equivalent. Newer versions of Java are untested.) Maven (Apache Maven 3.8.6 or greater)

Looks very interesting!