Chapter 2. Non-interactively selecting a system-wide Red Hat build of OpenJDK version on RHEL
If you have multiple versions of Red Hat build of OpenJDK installed on RHEL, you can select the default Red Hat build of OpenJDK version to use system-wide in a non-interactive way. This is useful for administrators who have root privileges on a Red Hat Enterprise Linux system and need to switch the default Red Hat build of OpenJDK on many systems in an automated way.
If you do not have root privileges, you can select a Red Hat build of OpenJDK version by configuring the JAVA_HOME
environment variable.
Prerequisites
- You must have root privileges on the system.
-
Multiple versions of Red Hat build of OpenJDK were installed using the
yum
package manager.
Procedure
Select the major Red Hat build of OpenJDK version to switch to. For example, for Red Hat build of OpenJDK 11, use
java-11-openjdk
.# PKG_NAME=java-11-openjdk # JAVA_TO_SELECT=$(alternatives --display java | grep "family $PKG_NAME" | cut -d' ' -f1) # alternatives --set java $JAVA_TO_SELECT
Verify that the active Red Hat build of OpenJDK version is the one you specified.
$ java -version openjdk version "11.0.9" 2020-10-15 LTS OpenJDK Runtime Environment 18.9 (build 11.0.9+10-LTS) OpenJDK 64-Bit Server VM 18.9 (build 11.0.9+10-LTS, mixed mode, sharing)