复制前端项目到后端项目内时，启动时发现org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat这个问题
具体错误如下：
2022-04-29 15:20:48.861 ERROR 20464 --- [ restartedMain] org.apache.catalina.core.ContainerBase : A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) [na:1.8.0_60]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) [na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) [tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) [na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:479) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) [spring-context-5.3.19.jar:5.3.19]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.7.jar:2.6.7]
at com.longtong.wj.WjApplication.main(WjApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_60]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_60]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_60]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_60]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.6.7.jar:2.6.7]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) [tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) [tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) [na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) [tomcat-embed-core-9.0.62.jar:9.0.62]
... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_60]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_60]
... 45 common frames omitted
2022-04-29 15:20:48.863 ERROR 20464 --- [ restartedMain] org.apache.catalina.core.ContainerBase : A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_60]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:479) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) [spring-context-5.3.19.jar:5.3.19]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.7.jar:2.6.7]
at com.longtong.wj.WjApplication.main(WjApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_60]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_60]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_60]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_60]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.6.7.jar:2.6.7]
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 26 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_60]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 34 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) [tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) [tomcat-embed-core-9.0.62.jar:9.0.62]
... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_60]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_60]
... 45 common frames omitted
2022-04-29 15:20:48.864 INFO 20464 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2022-04-29 15:20:48.874 WARN 20464 --- [ restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
2022-04-29 15:20:48.882 INFO 20464 --- [ restartedMain] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-04-29 15:20:48.904 ERROR 20464 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:163) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.19.jar:5.3.19]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) [spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) [spring-boot-2.6.7.jar:2.6.7]
at com.longtong.wj.WjApplication.main(WjApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_60]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_60]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_60]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_60]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.6.7.jar:2.6.7]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:142) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:479) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.6.7.jar:2.6.7]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.6.7.jar:2.6.7]
... 13 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.6.7.jar:2.6.7]
... 18 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_60]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 26 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:938) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 26 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_60]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:926) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 34 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_60]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134) ~[na:1.8.0_60]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 34 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) ~[tomcat-embed-jasper-8.5.23.jar:8.5.23]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5219) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.62.jar:9.0.62]
... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_60]
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_60]
at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_60]
... 45 common frames omitted
Process finished with exit code 0 
看cause by 就会发现内嵌的tomcat无法启动，然后就是重复一大堆版本号，那就说明版本号有问题了（你的tomcat版本和springboot版本不兼容），看看你是不是版本错了。一般修改tomcat版本为它建议的版本，也就是图中反复出现的版本号，问题就解决了。
