Since v6.1 OpenXava needs Java 8 or better
Java 6 (until v6.0.2)
By default, OpenXava is compiled with Java 6, so you can use OpenXava with
WebSphere 8 and WebLogic 10. However, the application server included in
the OpenXava distribution is Tomcat 9 (since OpenXava 6) that requires
Java 8. Therefore, you need to use Java 8 (or better) to follow the
introduction documentation to OpenXava.