Springboot3整合myBatisplus报错：Bean named ‘ddlApplicationRunner‘ is expected to be of type ‘org.sprin

1、错误：

我用Springboot3.1.7整合myBatisplus3.5.3时，出现下面的错误：

Bean named ‘ddlApplicationRunner’ is expected to be of type ‘org.springframework.boot.Runner’ but was actually of type ‘org.springframework.beans.factory.support.NullBean’

明明我的代码刚开始写，就起了一个头，竟然报错了！

demo框架如下：

(1)Demo1Application.java

(2)controller层：JOJOController.java

(3)service层：JOJOService.java