openxava / documentation / Java 21

By default, OpenXava is compiled with Java 8, so you can use OpenXava with Java 8, 11 or 17. Moroever, since v7.2 OpenXava supports Java 21, therefore you can compile and run your OpenXava applications with Java 21 and enjoy their new features.
To use Java 21 in your application you have to change the compile level in the pom.xml of your project, thus:
The below instructions are for configuring OpenXava Studio to use Java 21. Obviously, you should have JDK 21 installed on your computer.

Add Java 21 to OpenXava Studio

The first step is to indicate to OpenXava Studio where the JDK 21 is installed. For that, go to Window > Preferences > Java > Installed JREs, and there add the JDK 21 to the Installed JREs list:eclipse-installed-jres-java21.png
It's not needed that you mark it as the defaul JRE.

Configure to compile with Java 21

You should define your own Maven configuration to compile, package or install your application and indicate in that configuration that you're going to use Java 21. Use that configuration for compile or package your application. That is, do a right mouse click on your project, and choose Run As > Maven build..., then in the dialog create a configuration to call the goal package and named it yourproject package21 (for example), in this way:
The go to the JRE tab and in Alternate JRE option, choose the JDK 21 as JRE, thus:
Now click on Run and your application will be compiled and packaged using Java 21. From now on, you can use the compile21 configuration you have created to compile with Java 21.

Configure to run with Java 21

You have to edit your run configuration to use the JDK 21 to run your application. For that click on the Run Configuration... menu entry:
Choose your application on the right, on the Java Application section. Then go to the JRE tab and in Alternate JRE choose the JDK 21, like this:
Click on Run, and your application will run using Java 21.

Note: Beware, because if you do a Maven > Upgrade Project on your project at any moment, your project will be marked with errors. Don't panic, just do a right click on your project, and choose Properties > Java Build Path > Libraries. There remove the Java 18 JRE library and add the Java 21 library, with the Add Library... button.