Java SE support
Open Liberty requires a Java SE runtime. It can run by using either a JRE (Java Runtime Environment) or a JDK (Java SE Development Kit) distribution. Open Liberty runs on any of the Java SE versions that are listed in the following sections.
Always run Open Liberty on the most recent service release of your chosen Java version. A new version of Java SE is released every six months. Unless the prior version is designated as a Long Term Support (LTS) release, it no longer receives service updates for function and security. Currently, the only LTS releases are Java SE 8 and 11. Whenever a non-LTS release is replaced by the next version, the Open Liberty project no longer validates the runtime against the older version.
Open Liberty runs on Java SE 11.0.3 or newer. Keep in mind, Eclipse OpenJ9, which is available for free from IBM Semeru, has a better memory footprint and startup profile than HotSpot. For more information, see Open Liberty and Java 11.
Due to differences between Java SE 8 and Java SE 11, an Open Liberty application that runs on Java SE 8 might not run on Java SE 11. For more information, see Oracle Java SE 11 migration guide.
Open Liberty runs on any recent Java SE 15 release. Java SE 15 is not a long-term supported release and standard support is scheduled to end in March 2021. Keep in mind, if you download your Java SDK from AdoptOpenJDK, Eclipse OpenJ9 has a better memory footprint and startup profile than HotSpot. For more information, see Open Liberty and Java 11.