Imagine, you are tasked with maintaining a Java application that needs to run on more than one Java version. You want to ensure that it compiles, tests and builds on all of them.
This is our story, buckle up, there are a few moving parts

The big picture

• We use Apache Maven to drive the project using the pom.xml
• The Maven Toolchains plugin controls the Java versions
• Using <properties> ... </properties> and Build Profiles to adjust conditions for processing
• Annotatiosn like @Only8 and @Only17 help to qualify tests
• Our build tool (Jenkins or Github Actions) will use a container provided (in our case based on Redhat UBI)