How to update the Java Runtime on the RoboRIO?

Technical Programming
1

According to the WPILib New for 2019 page, the control system should be using Java 11 this year. We’ve got our GradleRIO build deploying to our robot with JDK 11, but get an UnsupportedClassVersionError in the driver station, saying that class version 55 (Java 11) is not supported; only up to 52 (Java 8). We’ve imaged the RIO, and updated all the tools we can think of, but it still seems that our robot is running on JRE 8.

Does anyone know how to update this? Or should we still be compiling with JDK 8 despite what the WPILib page says?

2

Are you using the 2019 release of WPILib and GradleRIO? The alpha used and deployed JDK8. You have to format the RoboRIO with 2019 and deploy with WPILib 2019 to get JDK11 on the Rio. There is a manual process that’s possible to use, but the automatic process should work if you are using all 2019 versions.

2 Likes
3

Solved by updating GradleRIO, we missed that somehow. Thanks for the help.