Spring boot is used this time, and errors are reported when the project is started. Since I use JDK 1.7 and the default of the project is JDK 1.8, I need to change the following series of configurations. No more nonsense. Above:

    It is found that the project environment is not fully configured. Open file – “project structuer”, find the project, and configure the JDK in it as your own.

     There are also these items in modules:

      Then find in file – “setting –” java compiler

These are all configured to start the main function and start the service