spring：Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/core/metrics/ApplicationStartup

 设置了父类框架

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<parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-starter-parent</artifactId>        <version>2.1.10.RELEASE</version>        <relativePath/> <!-- lookup parent from repository -->    </parent>

　　将其删除后可用

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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">     <modelVersion>4.0.0</modelVersion>         <groupId>org.example</groupId>     <artifactId>spring</artifactId>     <version>1.0-SNAPSHOT</version>                    <dependencies>         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-context</artifactId>             <version>5.3.7</version>         </dependency>         <dependency>             <groupId>com.alibaba</groupId>             <artifactId>druid</artifactId>             <version>1.1.23</version>         </dependency>         <dependency>             <groupId>mysql</groupId>             <artifactId>mysql-connector-java</artifactId>             <version>5.1.49</version>         </dependency>         <dependency>             <groupId>org.mybatis</groupId>             <artifactId>mybatis</artifactId>             <version>3.5.5</version>         </dependency>         <dependency>             <groupId>org.springframework</groupId>             <artifactId>spring-jdbc</artifactId>             <version>5.2.13.RELEASE</version>         </dependency>         <dependency>             <groupId>org.mybatis</groupId>             <artifactId>mybatis-spring</artifactId>             <version>2.0.5</version>         </dependency>         <dependency>             <groupId>javax.servlet</groupId>             <artifactId>javax.servlet-api</artifactId>             <version>4.0.1</version>         </dependency>         <dependency>             <groupId>org.aspectj</groupId>             <artifactId>aspectjweaver</artifactId>             <version>1.9.6</version>         </dependency>         <dependency>             <groupId>commons-logging</groupId>             <artifactId>commons-logging</artifactId>             <version>1.2</version>         </dependency>     </dependencies>   </project>