Specify JAVA_HOME in Jenkins for Java 11

Question

I have several projects running in Java 1.8 and Jenkins groovy script + Ansible acting as a pipleine to do deploys. Some of the projects are now migrated to Java 11 (OpenJDK). How do I configure Jenkins to build these projects in migrated to Java 11?

Answer 1

First you need to add java 11 jdk by going to Manage Jenkins menu. This will fix the build issues.

For groovy script: You cannot set JAVA_HOME in jenkins and expect maven to pick up correctly. It wont work. The successful approach was to add this in the pipeline:

env.JAVA_HOME="${tool 'openjdk_11_0_1'}"
env.PATH="${env.JAVA_HOME}/bin:${env.PATH}"

"openjdk_11_0_1" beeing the name of the java configuration initially registered into Jenkins

Answer 2

In Jenkins 2.x, under Jenkins | Manage Jenkins | Global Tool Configuration,
you should find a section " JDK Installations ".

Configure multiple your jdk there. I'd not recommend "Install automatically" for Oracle JDK given their licensing changes since April 2019.

This question describes handling multiple jdk in a pipeline .

Corresponding the names in the image example the tools values would be:

  tools {
    jdk 'jdk1.8'
    jdk 'jdk1.6'
  }

For maven,

Use a maven toolchain / profiles to be able to dynamically choose which to use: https://maven.apache.org/guides/mini/guide-using-toolchains.html

https://maven.apache.org/plugins/maven-compiler-plugin/examples/compile-using-different-jdk.html

ps: for freestyle jobs, the choice in in the General tab:

Note: if only one JDK is available, the option is hidden .

Answer 3

In Jenkins > Manage Jenkins > Configure System > Global properties > Add environment variable. JAVA_HOME environment variable