Java version on Mac documentation

[krekr]

I couldn't get the configurator.jar to run, turned out I had a very old (2020) version of Java installed that came with MacOS. If you double-click the .jar in Finder, you'll get a generic error. Using the command line results in:
Error: LinkageError occurred while loading main class com.airepublic.bmstoinverter.configurator.Configurator java.lang.UnsupportedClassVersionError: com/airepublic/bmstoinverter/configurator/Configurator has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 59.0

What made it even more difficult to troubleshoot was that the error referred to the Java runtime (JRE) which you can download here but doesn't fix the error;

Turns out you need to download the JDK (NOT JRE) and link that in your shell:
/usr/libexec/java_home -V
nano ~/.zshrc
Add:
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-23.jdk/Contents/Home #export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-15.0.1.jdk/Contents/Home export PATH=$JAVA_HOME/bin:$PATH
Reload shell:
source ~/.zshrc
Check if new version actually runs:
java -version java version "23" 2024-09-17 Java(TM) SE Runtime Environment (build 23+37-2369) Java HotSpot(TM) 64-Bit Server VM (build 23+37-2369, mixed mode, sharing)

Documenting this here for future generations :) Might be something to put in doc.

[krekr]

Something similar applies to armhf / armv6 / armv7 for the target; as far as I can tell there is no JDK version for those environments that is new enough to support this software. I was using a Pi Zero W; now switched to Pi4.

[ai-republic]

Hi @krekr,
yes, thanks for this clarification and sharing this. I will update the documentation accordingly 😄

On your comment I actually downgraded the minimum requirements to JDK 8 so that people with a 32-bit microcontroller can use this software!

Is recommended though to use a 64bit Java JDK 21+ and a 64bit operating system.