There are separate run and job execution requirements for Jenkins installations.
Modern Jenkins versions have the following Java requirements:
Java 8 is the ONLY currently supported runtime environment, both 32-bit and 64-bit versions are supported
Older versions of Java are not supported
Java 9 and Java 10 are not supported
Java 11 preview support is available in Jenkins 2.155+
This page provides guidelines about running Jenkins with these versions
Java 12 is not supported
These requirements apply to all components of the Jenkins system including Jenkins master, all types of agents, CLI clients, and other components.
Jenkins project performs a full test flow with the following JDK/JREs:
OpenJDK JDK / JRE 8 - 64 bits
JRE/JDKs from other vendors are supported and may be used. See our Issue tracker for known Java compatibility issues.
Jenkins jobs may be executed on Java versions different from the master/agent runtime. Generally, Jenkins allows ANY version of JRE/JDK to be invoked during the build. It includes:
Execution of Java commands from CLI
Installation and execution of build steps based on the plugin:jdk-tool plugin
In the case of particular plugins, there are still Java requirements:
If you use Maven Integration Plugin, version of JDK used for the build must be equal to the version used by Jenkins
If you use Swarm Plugin to create agents, JRE version must be equal to the version of the master
If you use Docker Pipeline Plugin with a bundled JRE/JDK to execute jobs, versions of such bundled Java must be equal to the version of the master
Modern versions of Jenkins master and agents verify Java requirements and notify users when they are launched with unsupported version.
In order to do fine-grain monitoring of Java versions on agents, you can use Jenkins Versions Node Monitors plugin to setup Java version monitoring across the Jenkins system.