How to install Java Runtime Environment (JRE) on openSUSE and SLES

Java applications ship as bytecode, so an openSUSE or SLES host cannot start a JAR file or vendor server application until it has a Java Runtime Environment (JRE). zypper installs one from the OpenJDK packages in the distribution repositories, and the resulting java command receives security fixes with the rest of the system's packages.

Runtime package names carry the Java release number, as in java-21-openjdk-headless, which covers server and terminal-launched applications. Only a desktop application needs java-21-openjdk, which adds the X11 and font libraries for drawing windows.

The newest release on offer differs by distribution, with openSUSE Leap 15.6 stopping at Java 21 while Tumbleweed and SLES 16 also carry Java 25. SLES hosts receive their online repositories through registration with SUSE, so the OpenJDK packages may not appear until the server is registered. None of these runtime packages include the javac compiler, so building from source needs the JDK instead.

1. Open a terminal with sudo privileges.
2. Refresh the zypper repository metadata.

   $ sudo zypper refresh
   Retrieving repository 'SLE_BCI' metadata [done]
   Building repository 'SLE_BCI' cache [done]
   All repositories have been refreshed.

   Repository names vary by openSUSE or SLES release. zypper should finish with refreshed repository metadata.

3. Search for the required OpenJDK runtime package.

   $ zypper search --details java-21-openjdk-headless
   Loading repository data...
   Reading installed packages...
   
   S  | Name                     | Type    | Version              | Arch    | Repository
   ---+--------------------------+---------+----------------------+---------+-----------
      | java-21-openjdk-headless | package | 21.0.11.0-160000.1.1 | aarch64 | SLE_BCI

   If the application requires another supported major version, search for that package name, such as java-17-openjdk-headless. Install the full java-21-openjdk package instead only when a desktop Java application needs graphical runtime libraries.

4. Install the OpenJDK runtime package.

   $ sudo zypper --non-interactive install java-21-openjdk-headless
   Loading repository data...
   Reading installed packages...
   Resolving package dependencies...
   
   The following 23 NEW packages are going to be installed:
     file file-magic findutils java-21-openjdk-headless javapackages-filesystem
     javapackages-tools mozilla-nss mozilla-nss-certs update-alternatives
     ##### snipped #####
   
   23 new packages to install.
   Package download size: 50.8 MiB
   ##### snipped #####

5. Confirm that the java command is available in the shell path.

   $ command -v java
   /usr/bin/java

6. Verify the installed OpenJDK runtime.

   $ java --version
   openjdk 21.0.11 2026-04-15
   OpenJDK Runtime Environment (build 21.0.11+10-suse-160000.1.1-aarch64)
   OpenJDK 64-Bit Server VM (build 21.0.11+10-suse-160000.1.1-aarch64, mixed mode)

   Security updates change the exact update number. java should run and report the OpenJDK major version expected by the application.

7. Select the default runtime only when more than one Java runtime is installed.

   $ sudo update-alternatives --config java

   After changing the default, rerun java --version to confirm that /usr/bin/java points to the runtime the application requires.