1.導入已存在的mavne項目
2.設置jdk
.settings
settings
>Build,Exception,Deployment
>Java Compiler
>Per-modeule bytecode version
2.Project Structure
Project Structure>Project SDK
Project Structure>Project language level
Project Structure>Modules>{your project}>Sources>Language Level
Project Structure>Modules>{your project}>Sources>Dependency>Module SDK
3.第二步錯誤:idea modules must not contains *
The root already belongs to module ,
直接把main和test刪掉
4.Junit報錯:org.junit不存在
打開工程結構 File>Project Structure
選擇目標工程, 在右邊欄中點擊 Dependencies, 將unit的scope設置爲Compile。