2021-08-20 16:18:57.650 ERROR 9476 --- [ 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[]]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
2021-08-20 16:18:57.652 ERROR 9476 --- [ 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
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext
Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
2021-08-20 16:18:57.652 INFO 9476 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2021-08-20 16:18:57.663 WARN 9476 --- [ 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
2021-08-20 16:18:57.673 INFO 9476 --- [ restartedMain] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-08-20 16:18:57.688 ERROR 9476 --- [ 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-2.5.3.jar:2.5.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.9.jar:5.3.9]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:338) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332) ~[spring-boot-2.5.3.jar:2.5.3]
at com.example.xmspringboot.XmSpringbootApplication.main(XmSpringbootApplication.java:10) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.5.3.jar:2.5.3]
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-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:450) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:199) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.5.3.jar:2.5.3]
... 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:940) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:437) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:934) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.5.3.jar:2.5.3]
... 18 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:na]
at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:928) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
... 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:940) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1388) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:921) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
... 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.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:na]
at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:928) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
... 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-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1398) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1388) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:921) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
... 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-9.0.50.jar:9.0.50]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.50.jar:9.0.50]
... 40 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:604) ~[na:na]
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) ~[na:na]
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) ~[na:na]
... 45 common frames omitted
Unable to start embedded Tomcat，不能启动tomcat，应该是版本兼容性问题。
ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser，加载不到这个类，看看是不是有这个依赖，没有的话，加进来再启动