Jabref 5: today's development version won't start

[wujastyk]

Steps to reproduce the behavior:

1. $java -jar ./JabRef--master--latest.jar [today's version, 2019-08-27]

output:

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/jabref/JabRefLauncher has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:495)

[Siedlerchr]

JabRef now requires java 11 as minimum version (since release of alpha). So you can now finally upgrade to openjdk11

[AEgit]

JabRef 5.0-dev--snapshot--2019-08-27--master--84436d795
Windows 10 10.0 amd64
Java 11.0.4-bellsoft

I can confirm this issue when JabRef is started from the command line as invoked above (under Windows).

If JabRef is started like a normal GUI application using a shortcut, there appear to be no issues.

[tobiasdiez]

You need to modify the JAVA_HOME environment variable to point to your java 11 installation (or specify the complete path for the java executable).

[Siedlerchr]

@AEgit That's probably because you have an old java version still in your environment path variables.
Check the system and user environment variables. Simply remove the java 8 entries or move the java 11 path to the top.

[AEgit]

@tobiasdiez and @Siedlerchr : Cheers, thanks for the advice! I personally will not change anything at the moment, since I generally don't start JabRef from the command line anyway (at least under Windows - it is different for Linux). But your comments should help @wujastyk to overcome the problem.

[wujastyk]

I installed openjdk11, un-hold'ed the three version 8 openjfx files, and now Jabref 5 testversion starts just fine.
Jabref 4.3.1 now doesn't load (it needs openjdk8, which is installed but not being found, I guess).

[wujastyk]

At present, to switch between JR5 testversion and JR 4.3.1 release one has to have both openjdk-11 and -8 installed, and switch between them with
sudo update-alternatives --config java
When going to version 8, one also has to manually "hold" the three openjfx files to version 8, and unhold them when going to version 11.

These procedures make it tiresome to switch between the release and test versions of JR, and therefore since I use JR for daily work, I will not often report on JR5 use.

[AEgit]

Have you tried running the Snap package for JR5? I haven't tried it myself, but as far as I understand the Snap architecture, exactly this use case should be covered, i. e. you shouldn't need to switch manually between the versions.

[wujastyk]

That's a really good idea. I've installed it (--edge), and it works fine. Thanks! I am uncertain how often the --edge snap is updated, but we'll see. Best, Dominik