注意检查各处的jdk版本设置

Preferences | Build, Execution, Deployment | Build Tools | Maven | Runner

Preferences | Build, Execution, Deployment | Compiler | Java Compiler
target bytecode version
project bytecode version
per-module bytecode version



file / project structure
project 
  SDK
  language level
modules 
  dependecies
    module SDK
  sources
    language level

platform settings
  SDKs



建议maven pom 里直接 指定jdk版本


  <properties>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
    <java.version>1.8</java.version>
  </properties>


java.version  是 springboot 的

maven.compiler.source  11