OpenWebStart/Java 11 migration

[Don-vip]

Things are starting to take shape with what comes after Java WebStart (see #16047):

​https://openwebstart.com/

On the current roadmap, the first version will be released end of October. A macro planning for a Java 8 => Java 11 transitions for all JOSM users would roughly look like this:

• September 2019: we start testing OpenWebStart on all platforms. Likely we'll found a lot of bugs
• November 2019 : first OpenWebStart version. Unlikely to fix all bugs we'll find
• Somewhere in 2020: OpenWebStart version without any bug impacting us, we start asking everyone to switch
• End of 2020: End of Java WebStart support by Oracle for Java 8. We force everyone to switch
• Somewhere in 2021: Enough JOSM users have switched to OpenWebStart so we can consider moving the codebase to Java 11.

[Don-vip]

First problem: #17632

[Don-vip]

First alpha version (0.2.0) is available for download: ​https://openwebstart.com/download/

[mdk]

Version 1.1.1 is released (at 16.12.2019)

[Don-vip]

Second problem: #18390 => ​https://github.com/AdoptOpenJDK/IcedTea-Web/pull/564 => ​https://github.com/AdoptOpenJDK/IcedTea-Web/releases/tag/icedtea-web-2.0.0-alpha9 => ​https://github.com/karakun/OpenWebStart/releases/tag/v1.1.4

[Don-vip]

AdoptOpenJDK API now available through https://josm.openstreetmap.de/remote/adoptopenjdk-api/ (#18723)

[Don-vip]

​https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes/

As of 18.04.4, OpenJDK 11 is the default in 18.04.

OpenJDK 8 has moved to universe and will remain available there for the life of 18.04, to provide migration time for packages, custom applications, or scripts that can't be build with OpenJDK 11. OpenJDK 8 will be updated in 18.04 until Ubuntu 16.04 LTS reaches EOL in April 2021.

[Don-vip]

Another issue: #18737 => ​https://github.com/AdoptOpenJDK/IcedTea-Web/issues/595

[Don-vip]

AdoptOpenJDK officially refused to ship OpenJFX in their binary distributions:
​https://github.com/AdoptOpenJDK/TSC/issues/27#issuecomment-607663428

So the best distribution for us would be ​Azul Zulu and ​Bellsoft's Liberica.

[taylor.smock]

Another issue: #19044 (Azul Zulu 11.0.6/AdoptOpenJDK 11.0.6). It looks like jdk.swing.interop.SwingInterOpUtils doesn't exist, for whatever reason. Oddly enough, it is never directly called by us (its called by JFXPanel, which is in the java distribution). I haven't filed a bug upstream, since I haven't run with a "standard" version of Azul Zulu yet.

EDIT: Not reproducible with Azul Zulu or AdoptOpenJDK from CLI.

Possibly related to ​https://github.com/AdoptOpenJDK/IcedTea-Web/issues/595 .

[mdk]

It looks like ​​https://github.com/AdoptOpenJDK/IcedTea-Web/issues/595 is fixed in the actual release 1.1.7