File -> Project Structure -> Project Settings>>Project>Project language 应与JDK吻合
File -> Project Structure -> Project Settings>>Modules>Modules language
File -> Settings -> Compiler -> Java Compiler -> Target bytecode version
File -> Project Structure -> Project Settings>>Project>Project language 应与JDK吻合
File -> Project Structure -> Project Settings>>Modules>Modules language
File -> Settings -> Compiler -> Java Compiler -> Target bytecode version