Refer to springboot startup error [extshutdown hook] – ask at the door – blog park

The main reason is package import error

No or wrong web initiator was imported

The processing method is as follows: import the following configuration into the POM file

       <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.4.4</version>
        </dependency>

Just run it again