It’s not too surprising but the upcoming Ubuntu 26.04 Long Term Support release will be transitioning to OpenJDK 25 as its default Java version.
Ubuntu 24.04 LTS and newer have been using OpenJDK 21 as their default version with the default-jdk package. OpenJDK 21 is a Long Term Support release on the Java side. Released back in September though was OpenJDK 25 as the newest LTS release.
Given OpenJDL 25 is the new LTS version, it’s not too surprising that Ubuntu 26.04 LTS will be moving ahead to that version as the default. Just a good sign they are moving ahead though as likely an indicator of little fallout in their testing thus far. The bug tracker notes at the moment of 15 packages failing to build with Java 25.
The java-common package was updated this week to make OpenJDK 25 the default JDK version in Ubuntu. That is currently in the Resolute’s proposed-main archive but should be working its way to main soon.
Over OpenJDK 21, OpenJDK 25 brings performance improvements, reduced memory usage, various garbage collection improvements, dropping of 32-bit x86 support, and various language enhancements. Overall a nice improvement for Java users to find as the new default beginning with Ubuntu 26.04 LTS this April.
