ssm项目运行报错，因为依赖或者环境版本？

问题遇到的现象和发生背景

ssm项目运行报错,请问怎么从报错信息里找出错误？

用代码块功能插入代码，请勿粘贴截图

运行结果及报错内容

2022-11-28 19:47:54.514 ERROR 7772 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/springframework/core/metrics/ApplicationStartup
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:224) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:146) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.boot.SpringApplication.createApplicationContext(SpringApplication.java:588) [spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:311) [spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) [spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at com.forest.demo.ForestLovePetsApplication.main(ForestLovePetsApplication.java:10) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_31]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_31]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_31]
    at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_31]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.3.4.RELEASE.jar:2.3.4.RELEASE]
Caused by: java.lang.NoClassDefFoundError: org/springframework/core/metrics/ApplicationStartup
    at org.springframework.beans.factory.support.AbstractBeanFactory.(AbstractBeanFactory.java:184) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.(AbstractAutowireCapableBeanFactory.java:176) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.(DefaultListableBeanFactory.java:193) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.context.support.GenericApplicationContext.(GenericApplicationContext.java:112) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
    at org.springframework.web.context.support.GenericWebApplicationContext.(GenericWebApplicationContext.java:97) ~[spring-web-5.3.20.jar:5.3.20]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.(ServletWebServerApplicationContext.java:117) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext.(AnnotationConfigServletWebServerApplicationContext.java:72) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_31]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_31]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_31]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:408) ~[na:1.8.0_31]
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:211) ~[spring-beans-5.3.20.jar:5.3.20]
    ... 11 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.core.metrics.ApplicationStartup
    at java.net.URLClassLoader$1.run(URLClassLoader.java:372) ~[na:1.8.0_31]
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361) ~[na:1.8.0_31]
    at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_31]
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360) ~[na:1.8.0_31]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_31]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) ~[na:1.8.0_31]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_31]
    ... 23 common frames omitted


Process finished with exit code 0

spring-core 包没引入吧

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看你的报错这一行，Caused by: java.lang.ClassNotFoundException: org.springframework.core.metrics.ApplicationStartup ，这个类 ApplicationStartup 没找到，一般是pom引包的问题，看下是少引用了包，还是引用包版本不一致导致的