springboot 提示The hierarchy of the type ** is inconsistent

SpringBoot startup prompt: The hierarchy of the type ** is inconsistent

Reason: The jar package where the class or its parent class is located has not been introduced

Suggested solution : start tracking the source code from the parent class of this class, find the jar package it is in and introduce it into the project

Generally it is because of lack of dependency to add dependency

    <!-- 集中定义管理依赖版本号 -->
	<properties>
		<servlet-api.version>3.1.0</servlet-api.version>
	</properties>
        <!-- 集成servlet -->
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>javax.servlet-api</artifactId>
			<version>${servlet-api.version}</version>
		</dependency>