I checked JDK16 repository in SpotBugs 4.2.0  I fixed only places in java.desktop module. I didn't fixed places, where dereferencing is done inside method.
------------- Commit messages: - 8231041: Spotbugs: Null check of value previously dereferenced in java.desktop Changes: https://git.openjdk.java.net/jdk/pull/1869/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1869&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8231041 Stats: 69 lines in 13 files changed: 13 ins; 36 del; 20 mod Patch: https://git.openjdk.java.net/jdk/pull/1869.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/1869/head:pull/1869 PR: https://git.openjdk.java.net/jdk/pull/1869