環境 $ java -version openjdk version "14-ea" 2020-03-17 OpenJDK Runtime Environment (build 14-ea+34-1452) OpenJDK 64-Bit Server VM (build 14-ea+34-1452, mixed mode, sharing) $ VER Microsoft Windows [Version 10.0.18362.592] JDK14 JDK 14 JEP 305: Pattern Matching for instanceof (Preview) JEP 305: Pat…
