JDK9 incompatibility: Error: Could not find or load main class org.jabref.JabRefMain

[jonasstein]

After fetching the latest jabref today (2017-07-28) it does not start anymore.

Fetch with:
wget https://builds.jabref.org/master/JabRef--master--latest.jar -O jabref.jar -o jabref_update.log

start with:

java -jar jabref.jar 
Error: Could not find or load main class org.jabref.JabRefMain

see also: #2867, but openfx is installed.

System Linux Mint 18.2
$ dpkg -l | grep jre
ii  openjdk-8-jre:amd64                          8u131-b11-2ubuntu1.16.04.2                 amd64        OpenJDK Java runtime, using Hotspot JIT
ii  openjdk-8-jre-headless:amd64                 8u131-b11-2ubuntu1.16.04.2                 amd64        OpenJDK Java runtime, using Hotspot JIT (headless)
ii  openjdk-9-jre:amd64                          9~b114-0ubuntu1                            amd64        OpenJDK Java runtime, using Hotspot JIT
ii  openjdk-9-jre-headless:amd64                 9~b114-0ubuntu1                            amd64        OpenJDK Java runtime, using Hotspot JIT (headless)

$ dpkg -l | grep jfx
hi  libopenjfx-java                              8u60-b27-4                                 all          JavaFX/OpenJFX 8 - Rich client application platform for Java (Java libraries)
hi  libopenjfx-jni                               8u60-b27-4                                 amd64        JavaFX/OpenJFX 8 - Rich client application platform for Java (native libraries)
ii  openjfx                                      8u60-b27-4                                 amd64        JavaFX/OpenJFX 8 - Rich client application platform for Java

[Siedlerchr]

Which one of your java versions is set as default? (sudo update-alternatives --config java )

Jdk9 does not yet work with JabRef, see #2594

Edit2 :: The latest commits have only been some language files and a minor fix in the fetcher. So nothing important

[jonasstein]

Thank you, I just checked. Indeed it was JDK9, would it be possible to provide an appropriate error message?
Error: JDK9 required, see bug #2594

However I could start now with
$ /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java -jar jabref.jar
Perhaps it helps other Linux Mint (*buntu) users who got here.

[tobiasdiez]

I fear it is not possible to present a better error message. The error is thrown by java itself before anything one the side of Jabref is invoked. We are in a similar dead end as for the case where the JavaFX component was missing and where we were also not in the position to report a better error message.

[matthiasgeiger]

duplicate of #2594

[jonasstein]

Thank you for your comment on this. Just another idea: You could provide an jabreftester.jar
which just tests if the environment is fine for jabref. #3073

[ytzemih]

For me this problem seems to reoccur with JabRef 4.3.1 on Ubuntu 18.04:

With the OpenJDK version openjdk version "1.8.0_191" (/usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java), I get

java -jar /opt/jabref/JabRef-4.3.1.jar
Error: Could not find or load main class org.jabref.JabRefMain

With the Oracle version java version "1.8.0_201" (/usr/lib/jvm/java-8-oracle/jre/bin/java), I can start JabRef as usual.

Because of other reasons, I am normally using OpenJDK, and was just playing around this morning with sudo update-alternatives --config java to find a working configuration.

Hope it won't take much to find a fix for this. Best wishes.

[tobiasdiez]

@ytzemih see https://github.com/JabRef/help.jabref.org/issues/204

[ytzemih]

@ytzemih see JabRef/help.jabref.org#204

Great, thx!