#340 macOS 10.12 app doesn't work with Java 8

[William Russell]

I'm using macOS 10.12 and I'm unable to get the DrJava app to work. It seems like the original jar file was packaged up with Java 7, but I can't seem to downgrade my Java from 8 to 7. Do you guys have a work around to get this working on Java 8? Or do I need to essentially rebuild the app with Java 8, so that when it runs it is trying to use that verison?

[Robert Cartwright]

The class files in drjava.jar are compatible with Java 7, but a prime feature of Java is backward compatibility (which was partially abandoned in Java 9 but that is not relevant to this discussion). The simplest way to run DrJava is from the command line. Open a terminal and cd (change working directory) to the directory (folder) containing the drjava jar file that you want to execute. Then type the command

java -jar drjava-xxx.jar

where xxx is the versioning suffix on you drjava jar file. If you rename your drjava jar file to drjava.jar to make the command line invocation really simple:

java -jar drjava.jar

On Linux, I typically run drjava this way since I don't trust the file opening application for my window manager (unity) to use the right command.