Check IntelliJ Java version

The easiest way to control the version of Java IntelliJ IDEA uses is to set the IDEA_JDK environment variable.

On windows, the search order for a JRE to use is:

IDEA_JDK env variable

jre directory in the IntelliJ IDEA installation location

JDK_HOME env variable

JAVA_HOME env variable

On linux, the load order is:

IDEA_JDK env variable

JDK_HOME env variable

JAVA_HOME env variable

jre directory in the IntelliJ IDEA installation location

For windows, in the the bin directory of the IntelliJ IDEA installation directory, there is an idea.bat script that has the logic for setting the necessary properties including the JDK to use. Linux has an idea.sh script.