Show proper information message when OpenJFX is not installed

[tobiasdiez]

As reported in #1711 (comment) without the OpenJFX packages on linux a cryptic message "Error: Could not find or load main class org.jabref.JabRefMain" is displayed.

It would be nice if instead a proper error message referring to apt-get install openjfx is shown. Not sure if this exception is "catchable". Or maybe we should indeed create a installer for linux that also installs openjfx in the process. Alternatively, we could create a self-contained application that also includes a private JRE, gradle plugin.

[Siedlerchr]

Seems like you could simply check for a ClassNotFoundException:
http://stackoverflow.com/questions/12213929/how-to-detect-javafx-2-2-runtime-availability

[stefan-kolb]

We definitly need to fix this. If I just double click the Jar nothing happens and I don't even see an error message.

[Siedlerchr]

I will try around with it. Maybe we can show a simple Swing Message/Alert when the class is not found.

[Siedlerchr]

I searched a bit further and there is no real solution to this.
If we get the 4.0.0 release in one of the debian packages, we can maybe mark the openjfx package as required. Otherwise we have to explicit inform the user before installation and should add a thing in the release notes. (We already documented this in the installation docs https://help.jabref.org/en/Installation )

[tobiasdiez]

Ok, if it is not possible then it is not possible...

[ilippert]

I also encounter this on Fedora 25 (the beta version 4.0 stops with "Error: Could not find or load main class org.jabref.JabRefMain"). If I interpret the issue correctly, OpenJFX will not be installable easily soon on Fedora - and building it seems tricky (I did not yet succeed)

[Siedlerchr]

You should then install the oracle jdk/jre, here seems to be an guide:
https://ask.fedoraproject.org/en/question/59412/sticky-how-do-i-install-oracle-java/

[koppor]

Can you check if http://help.jabref.org/en/Installation#fedora-23-and-oracle-java does provide enough support? Am 27.04.2017 16:39 schrieb "ilippert" <[email protected]>:

…

I also encounter this on Fedora 25 (the beta version 4.0 stops with "Error: Could not find or load main class org.jabref.JabRefMain"). If I interpret the issue correctly, OpenJFX will not be installable easily soon on Fedora <https://bugzilla.redhat.com/show_bug.cgi?id=1145303> - and building it <https://github.com/gferon/openjfx-fedora> seems tricky (I did not yet succeed) — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2642 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABTafvgC6PS1v93s5SCxO4sOx_nUt7Mpks5r0KiSgaJpZM4Mbwwq> .

[ambro2]

I recently had the same problem on Fedora 25. I had to install the Oracle Java JRE and configure the alternatives to set the Oracle version the default.
The Oracle JRE is available from here: http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.html as rpm file.
The links on the Help site point to the Java Development Kit (JDK) which is not required unless you are developping programs in Java.

[ilippert]

Thanks @Siedlerchr @ambro2 @koppor. @Siedlerchr's link sufficed to get it work. Cheers