Regarding Java 16 support
While eclipse JDT now supports Java 16, it’s still not yet part of their latest official JDT release (available through their marketplace, not natively with their latest release). Version 4.20 is not yet official, and still in SNAPSHOT phase.
As of today, our plan is to wait for official integration into eclipse JDT release before providing its support in our Java Analyzer. This will consequently happen only after the release 2021-06 of eclipse IDE, planned for June 16, 2021.
To track progress on our side, you can follow our umbrella ticket here, which includes the feature we want to include with its support: MMF-2317
Now, please note that we don’t know yet which version of SonarQube it will be shipped with.
For SonarCloud, however, it will be available a few days after we release it.
Regarding Java 17 LTS support
Similarly, we will wait for its integration in eclipse JDT and to be part of an eclipse IDE release before moving on. If the same scenario than for Java 16 occurs, Java 17 will be released in September, eclipse 2021-09 is going to be released without its official support, and we will have to wait till the release of eclipse 2021-12 to integrate it in our analyzer.
I hope this answer your question,