Chapter 3. Selecting an installed OpenJDK version for a specific application

Some applications require a specific OpenJDK version to run. If multiple versions of OpenJDK are installed on the system using the yum package manager or portable bundle, you can select a OpenJDK version for each application where necessary by setting the value of the JAVA_HOME environment variable or using a wrapper script.

Prerequisites

  • Multiple versions of OpenJDK installed on the machine.
  • Ensure that the application you want to run is installed.

Procedure

  1. Set the JAVA_HOME environment variable. For example, if openjdk-8 was installed using yum:

    $ JAVA_HOME=/usr/lib/jvm/java-8-openjdk

    Note

    The symbolic link java-8-openjdk is controlled by the alternatives command.

  2. Do one of the following:

    • Launch the application using the default, system-wide configuration. 

      $ mvn --version
Apache Maven 3.5.4 (Red Hat 3.5.4-5)
Maven home: /usr/share/maven
Java version: 1.8.0_242, vendor: Oracle Corporation, runtime: /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.242.b08-0.el8_1.x86_64/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "4.18.0-147.3.1.el8_1.x86_64", arch: "amd64", family: "unix"

    • Launch the application specifying the JAVA_HOME variable: 

      $ JAVA_HOME=/usr/lib/jvm/java-8-openjdk mvn --version

Apache Maven 3.5.4 (Red Hat 3.5.4-5)
Maven home: /usr/share/maven
Java version: 1.8.0_242, vendor: Oracle Corporation, runtime: /usr/lib/jvm/java-8-openjdk-1.8.0.242.b08-0.el8_1.x86_64
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "5.4.12-200.el8_1.x86_64", arch: "amd64", family: "unix"