There are lots of Java versions out there and supporting all of them is just too hard to be done in a quality manner. Thus we only support a subset.

By "supported versions" we mean:

• XWiki runs fine on that Java version.
• Issues created for these versions of Java in JIRA are not closed as won't fix and we make a best effort to fix them.
• We include these versions in our tests (be them automated or manual).

Supported Java Versions

• Always support the current Java LTS as defined by Oracle. Specifically this means working actively to make XWiki work on it as soon as it’s available.
  • e.g. in November 2023, the current Java LTS is Java 21.

  • There are several issues with Java 17+ but they can be worked around by passing the following JVM parameters (they are automatically passed when using the Standalone packaging start scripts):

    --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/java.io=ALL-UNNAMED --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.util.concurrent=ALL-UNNAMED

    List of Java 17-related issues:
• Keep supporting the previous LTS of Java too.
  • e.g. in November 2023, the previous LTS is Java 17.

Notes:

• Java LTS cycle are every 3 years so that seems a good cadence for us to move Java source versions too.
• We support the previous LTS since we want to be "business"-friendly and know that businesses take some time to upgrade.

By XWiki Versions

1. ^ When --add-opens directives are correctly set
2. ^ We're lagging behind and need to validate that latest XWiki 14.10.x and latest 15.x runs well with Java 21