Install instructions mention Java 11 but build expects Java 12

[egonw]

I'm following the build instructions from http://help.jabref.org/en/Installation#building-from-source (link given by the README), and running into a few issues. The first was easy to solve, but at least at Debian 10 you need to set JAVA_HOME (minor issue).

A bigger problem is that Java 11 does not seem enough anymore, and I get this error in the ./gradlew assemble step:

Found module name 'org.jabref'

> Task :compileJava FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Could not target platform: 'Java SE 12' using tool chain: 'JDK 11 (11)'.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 2m 6s
7 actionable tasks: 7 executed

[Siedlerchr]

Yes, sorry We recently upgraded to jdk 12 in #5426 and forgot to update the documentation

[Siedlerchr]

I upgraded the wiki part. If no jdk12 is avaiable in your repos you can install the version from here:
https://bell-sw.com/pages/java-12.0.2/
See you later ;)

[jairus-crabb]

Hi, I'm a newbie. I'm also experiencing this same issue. I initially started with Java 13 since Java stopped supporting it recently, but found this thread and switched over to Bell's Java 12 that you posted above.

Still receiving the exact same errors as the original poster. I've checked PATH, JAVA_HOME, etc. Followed all the instructions over at: https://github.com/JabRef/jabref/wiki/Guidelines-for-setting-up-a-local-workspace

Only thing I am thinking is that I'm not super familiar with IDEA, and that maybe my compiler overrides are not formatted correctly? Not sure if this would affect anything. I'll try a restart and give an update if that fixes.

[Siedlerchr]

Best is to ask in our gitter chat, there are some folks who use Intellij https://gitter.im/JabRef/jabref

[Krzmbrzl]

I just encountered the same issue when following these instructions: http://help.jabref.org/en/Installation

I downgraded to Java 11 via the build.gradle and was able to successfully build JabRef as per the instructions though. So I don't know if Java 12 is actually really required 🤔

[Siedlerchr]

@Krzmbrzl We explicitly moved to jdk12 in JabRef (although we previously used java 11 in the 5.0 alpha) to be able to check if it runs on newer jdks as well (13 does not yet work). And as the build tools now generates a custom jdk for running JabRef it's irrelevant for the end user which jdk he has installed.
So please change it to java 12 again.
https://builds.jabref.org/master

[tobiasdiez]

There are a few places in Intellij were one could select the JDK to run/compile the project. All of these have to be set to JDK 12 (or "use module/project").

For example:

• Build, Execution, Deployment > Compiler
• Project Settings > Project > Project SDK and Pattform Settings > SDK
• Edit run configuration

Hope this helps!