Develop Reference

Vaadin Starter Project doesnt run

I tried to run the starter Project of Vaadin in IntelliJ but only get following Error:
I have Vaadin installed and Maven, also the newest version of JDK.
I dont know why it doesnt work, i followed the full Starter Tutorial of Vaadin but only get this Errors
2023-01-13 10:53:04.578 ERROR 17752 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception sending context initialized event to listener instance of class [com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener]
java.lang.RuntimeException: Unable to initialize com.vaadin.flow.spring.VaadinServletContextInitializer$DevModeServletContextListener
at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:192) ~[vaadin-spring-23.3.2.jar:na]
at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.lambda$contextInitialized$0(VaadinServletContextInitializer.java:214) ~[vaadin-spring-23.3.2.jar:na]
at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
at com.vaadin.flow.spring.VaadinServletContextInitializer$CompositeServletContextListener.contextInitialized(VaadinServletContextInitializer.java:214) ~[vaadin-spring-23.3.2.jar:na]
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4767) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5231) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:265) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.68.jar:9.0.68]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:479) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:184) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:162) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.5.jar:2.7.5]
at com.example.application.Application.main(Application.java:22) ~[classes/:na]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:578) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.7.5.jar:2.7.5]
Caused by: java.lang.IllegalStateException: Failed to determine project directory for dev mode. Directory 'C:\j2ee\projekte\my-todo' does not look like a Maven or Gradle project. Ensure that you have run the prepare-frontend Maven goal, which generates 'flow-build-info.json', prior to deploying your application
at com.vaadin.base.devserver.startup.DevModeInitializer.getBaseDirectoryFallback(DevModeInitializer.java:404) ~[vaadin-dev-server-23.3.2.jar:na]
at com.vaadin.base.devserver.startup.DevModeInitializer.initDevModeHandler(DevModeInitializer.java:216) ~[vaadin-dev-server-23.3.2.jar:na]
at com.vaadin.base.devserver.DevModeHandlerManagerImpl.initDevModeHandler(DevModeHandlerManagerImpl.java:81) ~[vaadin-dev-server-23.3.2.jar:na]
at com.vaadin.flow.spring.VaadinServletContextInitializer$DevModeServletContextListener.failFastContextInitialized(VaadinServletContextInitializer.java:475) ~[vaadin-spring-23.3.2.jar:na]
at com.vaadin.flow.spring.VaadinServletContextInitializer$FailFastServletContextListener.contextInitialized(VaadinServletContextInitializer.java:188) ~[vaadin-spring-23.3.2.jar:na]
... 44 common frames omitted
2023-01-13 10:53:04.578 ERROR 17752 --- [ restartedMain] o.apache.catalina.core.StandardContext : One or more listeners failed to start. Full details will be found in the appropriate container log file
2023-01-13 10:53:04.579 ERROR 17752 --- [ restartedMain] o.apache.catalina.core.StandardContext : Context [] startup failed due to previous errors
2023-01-13 10:53:04.607 INFO 17752 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2023-01-13 10:53:04.610 WARN 17752 --- [ 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
2023-01-13 10:53:04.617 INFO 17752 --- [ restartedMain] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2023-01-13 10:53:04.635 ERROR 17752 --- [ 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:165) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.23.jar:5.3.23]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.5.jar:2.7.5]
at com.example.application.Application.main(Application.java:22) ~[classes/:na]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:578) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.7.5.jar:2.7.5]
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-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:479) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:184) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:162) ~[spring-boot-2.7.5.jar:2.7.5]
... 11 common frames omitted
Caused by: java.lang.IllegalStateException: StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[] failed to start
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.rethrowDeferredStartupExceptions(TomcatWebServer.java:187) ~[spring-boot-2.7.5.jar:2.7.5]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.7.5.jar:2.7.5]
... 16 common frames omitted
Process finished with exit code 0
I Tried everything, but cant find any solution.

This can happen if you import the parent directory in IntelliJ IDEA instead of importing the project directory itself

Looking at the stack trace, this caught my attention:
Caused by: java.lang.IllegalStateException: Failed to determine project directory for dev mode. Directory 'C:\j2ee\projekte\my-todo' does not look like a Maven or Gradle project. Ensure that you have run the prepare-frontend Maven goal, which generates 'flow-build-info.json', prior to deploying your application
Which might mean the problem lives in the pom.xml file. Are you importing vaadin-maven-plugin ? How did you generate this pom.xml ? Did you download it from an existing repository/project/example ?

spring boot 3.0.0 compatibility with keycloak-spring-boot-starter

I'm getting an error after adding keycloak-spring-boot-starter and removing spring security which I had originally. I switched because I thought the configuration was simpler and more opinionated.
To be honest I don't know what the difference between 3.0.0-M1 and 2.6.3 is. I'm trying to learn spring boot by creating a simple RESTful HTTP API that is protected by keycloak.
Is v3 recommended or should 2.6.3 be used? I'm finding it very hard to find appropriate, complete information in the Java world.
If you need any more info please comment.
startup log
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v3.0.0-M1)
2022-02-21 12:58:14.469 INFO 10181 --- [ restartedMain] de.icod.recipe.RecipeApplication : Starting RecipeApplication using Java 17.0.2 on dev.luketic with PID 10181 (/home/darko/IdeaProjects/recipe/target/classes started by darko in /home/darko/IdeaProjects/recipe)
2022-02-21 12:58:14.471 INFO 10181 --- [ restartedMain] de.icod.recipe.RecipeApplication : No active profile set, falling back to default profiles: default
2022-02-21 12:58:14.507 INFO 10181 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2022-02-21 12:58:14.508 INFO 10181 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2022-02-21 12:58:14.895 INFO 10181 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode.
2022-02-21 12:58:14.916 INFO 10181 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 16 ms. Found 1 JPA repository interfaces.
2022-02-21 12:58:15.417 INFO 10181 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 3000 (http)
2022-02-21 12:58:15.421 INFO 10181 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-02-21 12:58:15.421 INFO 10181 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.0.16]
2022-02-21 12:58:15.464 INFO 10181 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-02-21 12:58:15.465 INFO 10181 --- [ restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 956 ms
2022-02-21 12:58:15.491 ERROR 10181 --- [ 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.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:926) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:886) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
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-10.0.16.jar:10.0.16]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:478) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-6.0.0-M2.jar:6.0.0-M2]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:719) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:401) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1279) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at de.icod.recipe.RecipeApplication.main(RecipeApplication.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:77) ~[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:568) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-3.0.0-M1.jar:3.0.0-M1]
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-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
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-10.0.16.jar:10.0.16]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 34 common frames omitted
Caused by: java.lang.NoSuchMethodError: 'javax.servlet.ServletContext org.apache.catalina.Context.getServletContext()'
at org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve.keycloakInit(AbstractKeycloakAuthenticatorValve.java:111) ~[spring-boot-container-bundle-17.0.0.jar:17.0.0]
at org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve.lifecycleEvent(AbstractKeycloakAuthenticatorValve.java:70) ~[spring-boot-container-bundle-17.0.0.jar:17.0.0]
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:423) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:193) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 40 common frames omitted
2022-02-21 12:58:15.492 ERROR 10181 --- [ 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.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:926) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:478) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-6.0.0-M2.jar:6.0.0-M2]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:719) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:401) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1290) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1279) ~[spring-boot-3.0.0-M1.jar:3.0.0-M1]
at de.icod.recipe.RecipeApplication.main(RecipeApplication.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:77) ~[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:568) ~[na:na]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-3.0.0-M1.jar:3.0.0-M1]
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-10.0.16.jar:10.0.16]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:886) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
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-10.0.16.jar:10.0.16]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 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:926) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 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-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
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-10.0.16.jar:10.0.16]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 34 common frames omitted
Caused by: java.lang.NoSuchMethodError: 'javax.servlet.ServletContext org.apache.catalina.Context.getServletContext()'
at org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve.keycloakInit(AbstractKeycloakAuthenticatorValve.java:111) ~[spring-boot-container-bundle-17.0.0.jar:17.0.0]
at org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve.lifecycleEvent(AbstractKeycloakAuthenticatorValve.java:70) ~[spring-boot-container-bundle-17.0.0.jar:17.0.0]
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:423) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:193) ~[tomcat-embed-core-10.0.16.jar:10.0.16]
... 40 common frames omitted
2022-02-21 12:58:15.493 INFO 10181 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2022-02-21 12:58:15.499 WARN 10181 --- [ 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
2022-02-21 12:58:15.505 INFO 10181 --- [ restartedMain] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-02-21 12:58:15.515 ERROR 10181 --- [ restartedMain] o.s.b.d.LoggingFailureAnalysisReporter :
***************************
APPLICATION FAILED TO START
***************************
Description:
An attempt was made to call a method that does not exist. The attempt was made from the following location:
org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve.keycloakInit(AbstractKeycloakAuthenticatorValve.java:111)
The following method did not exist:
'javax.servlet.ServletContext org.apache.catalina.Context.getServletContext()'
The calling method's class, org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve, was loaded from the following location:
jar:file:/home/darko/.m2/repository/org/keycloak/spring-boot-container-bundle/17.0.0/spring-boot-container-bundle-17.0.0.jar!/org/keycloak/adapters/tomcat/AbstractKeycloakAuthenticatorValve.class
The called method's class, org.apache.catalina.Context, is available from the following locations:
jar:file:/home/darko/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/10.0.16/tomcat-embed-core-10.0.16.jar!/org/apache/catalina/Context.class
The called method's class hierarchy was loaded from the following locations:
org.apache.catalina.Context: file:/home/darko/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/10.0.16/tomcat-embed-core-10.0.16.jar
Action:
Correct the classpath of your application so that it contains compatible versions of the classes org.keycloak.adapters.tomcat.AbstractKeycloakAuthenticatorValve and org.apache.catalina.Context
Process finished with exit code 0
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.0.0-M1</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>de.icod</groupId>
<artifactId>recipe</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>recipe</name>
<description>recipe</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-rest</artifactId>
</dependency>
<dependency>
<groupId>org.keycloak</groupId>
<artifactId>keycloak-spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-rest-hal-explorer</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.keycloak.bom</groupId>
<artifactId>keycloak-adapter-bom</artifactId>
<version>17.0.0</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
</project>

My Java Spring Project build successfully but in the log give me error

I have java spring project. When I build the Project, project build successfully but in the log give me this error: - java.io.IOException: java.lang.reflect.InvocationTargetException. Тhe project is working properly. But I want to remove this error in the log when I build the project
Shows me that the problem is in this row in Application.java -
SpringApplication.run(Application.class, args);
This is my Application.java
package com.zetcode;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
import org.springframework.web.servlet.view.JstlView;
import org.thymeleaf.spring5.SpringTemplateEngine;
import org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.spring5.view.ThymeleafViewResolver;
import org.thymeleaf.templatemode.TemplateMode;
import javax.annotation.Resource;
#SpringBootApplication
public class Application extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Resource
protected ApplicationContext applicationContext;
#Resource
protected SpringTemplateEngine springTemplateEngine;
#Bean
public ThymeleafViewResolver thymeleafViewResolver(){
final ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
viewResolver.setViewNames(new String[] {"thyme/*"});
viewResolver.setExcludedViewNames(new String[] {"jsp/*"});
viewResolver.setTemplateEngine(springTemplateEngine);
viewResolver.setCharacterEncoding("UTF-8");
return viewResolver;
}
#Bean
public InternalResourceViewResolver jspViewResolver(){
final InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setViewClass(JstlView.class);
viewResolver.setPrefix("/templates/");
viewResolver.setSuffix(".jsp");
viewResolver.setViewNames("jsp/*");
return viewResolver;
}
#Bean
public SpringResourceTemplateResolver thymeleafTemplateResolver(){
final SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
templateResolver.setApplicationContext(applicationContext);
templateResolver.setPrefix("/templates/");
templateResolver.setSuffix(".html");
templateResolver.setTemplateMode(TemplateMode.HTML);
templateResolver.setCacheable(false);
templateResolver.setOrder(0);
return templateResolver;
}
#Bean
public SpringResourceTemplateResolver jspTemplateResolver(){
final SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
templateResolver.setApplicationContext(applicationContext);
templateResolver.setPrefix("/templates/");
templateResolver.setSuffix(".jsp");
templateResolver.setTemplateMode(TemplateMode.HTML);
templateResolver.setCacheable(false);
templateResolver.setOrder(1);
templateResolver.setCharacterEncoding("UTF-8");
return templateResolver;
}
}
This is the log
java.io.IOException: java.lang.reflect.InvocationTargetException
at org.apache.tomcat.util.compat.Jre9Compat.jarFileNewInstance(Jre9Compat.java:212) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.JarFileUrlJar.<init>(JarFileUrlJar.java:65) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.JarFactory.newInstance(JarFactory.java:49) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.StandardJarScanner.process(StandardJarScanner.java:374) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.StandardJarScanner.processURLs(StandardJarScanner.java:309) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.StandardJarScanner.doScanClassPath(StandardJarScanner.java:278) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.tomcat.util.scan.StandardJarScanner.scan(StandardJarScanner.java:229) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.jasper.servlet.TldScanner.scanJars(TldScanner.java:262) ~[tomcat-jasper-9.0.1.jar:9.0.1]
at org.apache.jasper.servlet.TldScanner.scan(TldScanner.java:104) ~[tomcat-jasper-9.0.1.jar:9.0.1]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:83) ~[tomcat-jasper-9.0.1.jar:9.0.1]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5098) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1429) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1419) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
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-9.0.12.jar:9.0.12]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:944) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:839) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1429) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1419) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
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-9.0.12.jar:9.0.12]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:944) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:261) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:770) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:370) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:106) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:414) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:540) ~[spring-context-5.1.2.RELEASE.jar:5.1.2.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.0.RELEASE.jar:2.1.0.RELEASE]
at com.zetcode.Application.main(Application.java:23) ~[classes/:na]
Caused by: java.lang.reflect.InvocationTargetException: null
at java.base/jdk.internal.reflect.GeneratedConstructorAccessor27.newInstance(Unknown Source) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481) ~[na:na]
at org.apache.tomcat.util.compat.Jre9Compat.jarFileNewInstance(Jre9Compat.java:209) ~[tomcat-embed-core-9.0.12.jar:9.0.12]
... 46 common frames omitted
Caused by: java.nio.file.NoSuchFileException: C:\Users\svetl\.m2\repository\com\sun\xml\bind\jaxb-impl\2.2.3-1\jaxb1-impl.jar
at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:85) ~[na:na]
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:103) ~[na:na]
at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:108) ~[na:na]
at java.base/sun.nio.fs.WindowsFileAttributeViews$Basic.readAttributes(WindowsFileAttributeViews.java:53) ~[na:na]
at java.base/sun.nio.fs.WindowsFileAttributeViews$Basic.readAttributes(WindowsFileAttributeViews.java:38) ~[na:na]
at java.base/sun.nio.fs.WindowsFileSystemProvider.readAttributes(WindowsFileSystemProvider.java:198) ~[na:na]
at java.base/java.nio.file.Files.readAttributes(Files.java:1842) ~[na:na]
at java.base/java.util.zip.ZipFile$Source.get(ZipFile.java:1160) ~[na:na]
at java.base/java.util.zip.ZipFile$CleanableResource.<init>(ZipFile.java:719) ~[na:na]
at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:239) ~[na:na]
at java.base/java.util.zip.ZipFile.<init>(ZipFile.java:169) ~[na:na]
at java.base/java.util.jar.JarFile.<init>(JarFile.java:346) ~[na:na]
... 51 common frames omitted
2021-07-02 19:50:03.839 INFO 15960 --- [ main] org.apache.jasper.servlet.TldScanner : At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
2021-07-02 19:50:03.849 INFO 15960 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2021-07-02 19:50:03.850 INFO 15960 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1918 ms
2021-07-02 19:50:03.874 INFO 15960 --- [ main] o.s.b.w.servlet.ServletRegistrationBean : Servlet dispatcherServlet mapped to [/]
2021-07-02 19:50:03.878 INFO 15960 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'characterEncodingFilter' to: [/*]
2021-07-02 19:50:03.878 INFO 15960 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2021-07-02 19:50:03.878 INFO 15960 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'formContentFilter' to: [/*]
2021-07-02 19:50:03.878 INFO 15960 --- [ main] o.s.b.w.servlet.FilterRegistrationBean : Mapping filter: 'requestContextFilter' to: [/*]
2021-07-02 19:50:03.916 WARN 15960 --- [ main] ion$DefaultTemplateResolverConfiguration : Cannot find template location: classpath:/templates/ (please add some templates or check your Thymeleaf configuration)
2021-07-02 19:50:04.196 INFO 15960 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2021-07-02 19:50:04.703 INFO 15960 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2021-07-02 19:50:04.706 INFO 15960 --- [ main] com.zetcode.Application : Started Application in 3.134 seconds (JVM running for 3.587)

You need to disable the embedded tomcat manifest scanning.
#Bean
public TomcatServletWebServerFactory tomcatFactory() {
return new TomcatServletWebServerFactory() {
#Override
protected void postProcessContext(Context context) {
((StandardJarScanner) context.getJarScanner()).setScanManifest(false);
}};
}
Original source: how to disable tomcat manifest scanning with spring boot?

Spring Boot application failed to start on Java 1.8 version

2021-01-31 16:47:19.244 INFO 2436 --- [ main] technicalblog.technicalblog : Starting technicalblog on DESKTOP-IIPG7TQ with PID 2436 (C:\Users\Gajanan\IdeaProjects\webapplication\target\classes started by Gajanan in C:\Users\Gajanan\IdeaProjects\webapplication)
2021-01-31 16:47:19.249 INFO 2436 --- [ main] technicalblog.technicalblog : No active profile set, falling back to default profiles: default
2021-01-31 16:47:19.334 INFO 2436 --- [ main] ConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext#4c6e276e: startup date [Sun Jan 31 16:47:19 IST 2021]; root of context hierarchy
2021-01-31 16:47:20.795 INFO 2436 --- [ main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration' of type [org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration$$EnhancerBySpringCGLIB$$b9db71a7] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2021-01-31 16:47:21.445 INFO 2436 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2021-01-31 16:47:21.475 INFO 2436 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2021-01-31 16:47:21.476 INFO 2436 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/8.5.34
2021-01-31 16:47:21.487 INFO 2436 --- [ost-startStop-1] o.a.catalina.core.AprLifecycleListener : The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: [C:\Users\Gajanan\.jdks\corretto-1.8.0_265\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\Program Files (x86)\Common Files\Intel\Shared Libraries\redist\intel64\compiler;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\NVIDIA Corporation\NVIDIA NvDLISR;C:\Android;C:\Users\Gajanan\AppData\Local\Programs\Microsoft VS Code\bin;C:\adb;C:\Program Files\Java\jdk-14.0.2\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;C:\Program Files\Git\cmd;C:\Program Files\Git\mingw64\bin;C:\Program Files\Git\usr\bin;C:\Program Files\Java\jdk-14.0.1\bin;C:\Users\Gajanan\AppData\Local\Microsoft\WindowsApps;C:\Users\Gajanan\AppData\Local\Programs\Microsoft VS Code\bin;C:\Users\Gajanan\AppData\Local\GitHubDesktop\bin;.]
2021-01-31 16:47:21.623 ERROR 2436 --- [cat-startStop-1] 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_265]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) [na:1.8.0_265]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1420) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1410) [tomcat-embed-core-8.5.34.jar:8.5.34]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_265]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_265]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
Caused by: java.lang.AbstractMethodError: org.apache.tomcat.util.descriptor.tld.TldRuleSet.getNamespaceURI()Ljava/lang/String;
at org.apache.tomcat.util.digester.Digester.addRuleSet(Digester.java:1601) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.DigesterFactory.newDigester(DigesterFactory.java:174) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:49) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:44) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:100) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:81) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5245) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
2021-01-31 16:47:21.624 ERROR 2436 --- [ main] 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]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_265]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_265]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:366) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:107) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:413) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) [spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at technicalblog.technicalblog.main(technicalblog.java:20) [classes/:na]
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1420) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1410) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_265]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_265]
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:950) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 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_265]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_265]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 8 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) [tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
Caused by: java.lang.AbstractMethodError: org.apache.tomcat.util.descriptor.tld.TldRuleSet.getNamespaceURI()Ljava/lang/String;
at org.apache.tomcat.util.digester.Digester.addRuleSet(Digester.java:1601) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.DigesterFactory.newDigester(DigesterFactory.java:174) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:49) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:44) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:100) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:81) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5245) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) [tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
2021-01-31 16:47:21.624 INFO 2436 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2021-01-31 16:47:21.625 WARN 2436 --- [ main] 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
2021-01-31 16:47:21.634 INFO 2436 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-01-31 16:47:21.637 ERROR 2436 --- [ main] 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:155) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.9.RELEASE.jar:5.0.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:780) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:333) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1277) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1265) [spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at technicalblog.technicalblog.main(technicalblog.java:20) [classes/:na]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:413) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
... 8 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:366) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:107) ~[spring-boot-2.0.5.RELEASE.jar:2.0.5.RELEASE]
... 13 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 15 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 17 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:950) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 19 common frames omitted
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]
at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[na:1.8.0_265]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_265]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 21 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1420) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1410) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) ~[na:1.8.0_265]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) ~[na:1.8.0_265]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_265]
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:950) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:872) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 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_265]
at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[na:1.8.0_265]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:942) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 8 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
Caused by: java.lang.AbstractMethodError: org.apache.tomcat.util.descriptor.tld.TldRuleSet.getNamespaceURI()Ljava/lang/String;
at org.apache.tomcat.util.digester.Digester.addRuleSet(Digester.java:1601) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.DigesterFactory.newDigester(DigesterFactory.java:174) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:49) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.tomcat.util.descriptor.tld.TldParser.<init>(TldParser.java:44) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:100) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:81) ~[tomcat-embed-jasper-9.0.41.jar:9.0.41]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5245) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.34.jar:8.5.34]
... 6 common frames omitted
Pom.xml file
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.upgrad</groupId>
<artifactId>webapplication</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<version>2.0.5.RELEASE</version>
<artifactId>spring-boot-starter-parent</artifactId>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>42.2.2</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.23.1-GA</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<version>9.0.41</version>
</dependency>
</dependencies>
</project>

You are trying to mix jars from Tomcat 8.5.34 (the default version of Tomcat used by Spring Boot 2.0.5) and Tomcat 9.0.41. Rather than specifying a version when declaring the dependency on tomcat-embed-jasper you should allow Spring Boot's dependency management to control the version. You can do this by omitting the <version>:
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<version>9.0.41</version>
</dependency>
Spring Boot's dependency management is available as you have used spring-boot-starter-parent as your project's parent:
<parent>
<groupId>org.springframework.boot</groupId>
<version>2.0.5.RELEASE</version>
<artifactId>spring-boot-starter-parent</artifactId>
</parent>
It's not directly related to you problem, but you should also remove the versions from your various spring-boot-starter-… dependencies. This will allow the version to be controlled by spring-boot-starter-parent.
If you want to use Spring Boot 2.4, you should change the version of the <parent> rather than overriding the versions of individual modules.

Seems to be the issue with version mismatch between the jars in your dependencies. Please try to remove the version from starter web. 2.4.1

Spring MySQL com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

I'm newbie in Java and trying to start local MySQL server for the web blog.
Problem being then i wanted to connect to database...
Please help to resolve that!
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>blog</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>blog</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
application.properties
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:8889/spring_web_blog
spring.datasource.username=root
spring.datasource.password=root
console
2020-09-26 16:01:39.669 INFO 2649 --- [ restartedMain] com.example.blog.BlogApplication
: Starting BlogApplication on MacBook-Pro-Urij.local with PID 2649
(/Users/yy/Downloads/blog/target/classes started by yy in /Users/yy/Downloads/blog)
2020-09-26 16:01:39.675 INFO 2649 --- [ restartedMain] com.example.blog.BlogApplication
: No active profile set, falling back to default profiles: default
2020-09-26 16:01:39.839 INFO 2649 --- [ restartedMain]
.e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set
'spring.devtools.add-properties' to 'false' to disable
2020-09-26 16:01:39.840 INFO 2649 --- [ restartedMain]
.e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2020-09-26 16:01:40.890 INFO 2649 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFERRED mode.
2020-09-26 16:01:40.976 INFO 2649 --- [ restartedMain] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 74ms. Found 1 JPA repository interfaces.
2020-09-26 16:01:42.137 INFO 2649 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2020-09-26 16:01:42.168 INFO 2649 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2020-09-26 16:01:42.170 INFO 2649 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.38]
2020-09-26 16:01:42.359 INFO 2649 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2020-09-26 16:01:42.359 INFO 2649 --- [ restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2519 ms
2020-09-26 16:01:42.700 INFO 2649 --- [ restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2020-09-26 16:01:42.771 INFO 2649 --- [ task-1] o.hibernate.jpa.internal.util.LogHelper : HHH000204: Processing PersistenceUnitInfo [name: default]
2020-09-26 16:01:42.857 INFO 2649 --- [ task-1] org.hibernate.Version : HHH000412: Hibernate ORM core version 5.4.21.Final
2020-09-26 16:01:42.865 WARN 2649 --- [ restartedMain] JpaBaseConfiguration$JpaWebConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
2020-09-26 16:01:43.126 INFO 2649 --- [ task-1] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.0.Final}
2020-09-26 16:01:43.418 INFO 2649 --- [ task-1] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2020-09-26 16:01:43.661 INFO 2649 --- [ restartedMain] o.s.b.d.a.OptionalLiveReloadServer : LiveReload server is running on port 35729
2020-09-26 16:01:43.742 INFO 2649 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ''
2020-09-26 16:01:43.744 INFO 2649 --- [ restartedMain] DeferredRepositoryInitializationListener : Triggering deferred initialization of Spring Data repositories…
2020-09-26 16:01:44.644 ERROR 2649 --- [ task-1] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Exception during pool initialization.
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:836) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:197) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:477) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:560) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) ~[HikariCP-3.4.5.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-3.4.5.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:180) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:68) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:176) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:118) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1224) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1255) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264) ~[na:na]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:835) ~[na:na]
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481) ~[na:na]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.NativeSession.connect(NativeSession.java:144) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:956) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:826) ~[mysql-connector-java-8.0.21.jar:8.0.21]
... 34 common frames omitted
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na]
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na]
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403) ~[na:na]
at java.base/java.net.Socket.connect(Socket.java:591) ~[na:na]
at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.21.jar:8.0.21]
at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65) ~[mysql-connector-java-8.0.21.jar:8.0.21]
... 37 common frames omitted
2020-09-26 16:01:44.645 WARN 2649 --- [ task-1] o.h.e.j.e.i.JdbcEnvironmentInitiator : HHH000342: Could not obtain connection to query metadata : Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
2020-09-26 16:01:44.652 WARN 2649 --- [ restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'postRepository' defined in com.example.blog.repo.PostRepository defined in #EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot resolve reference to bean 'jpaMappingContext' while setting bean property 'mappingContext'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
2020-09-26 16:01:44.654 INFO 2649 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2020-09-26 16:01:44.655 WARN 2649 --- [ restartedMain] o.s.b.f.support.DisposableBeanAdapter : Invocation of destroy method failed on bean with name 'entityManagerFactory': org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
2020-09-26 16:01:44.655 INFO 2649 --- [ restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor'
2020-09-26 16:01:44.668 INFO 2649 --- [ restartedMain] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2020-09-26 16:01:44.754 INFO 2649 --- [ restartedMain] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-09-26 16:01:44.758 ERROR 2649 --- [ restartedMain] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'postRepository' defined in com.example.blog.repo.PostRepository defined in #EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot resolve reference to bean 'jpaMappingContext' while setting bean property 'mappingContext'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:342) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:113) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1697) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1442) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:624) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:612) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.data.repository.config.DeferredRepositoryInitializationListener.onApplicationEvent(DeferredRepositoryInitializationListener.java:51) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.data.repository.config.DeferredRepositoryInitializationListener.onApplicationEvent(DeferredRepositoryInitializationListener.java:36) ~[spring-data-commons-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:404) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:361) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:898) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:554) ~[spring-context-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.4.RELEASE.jar:2.3.4.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[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.example.blog.BlogApplication.main(BlogApplication.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-2.3.4.RELEASE.jar:2.3.4.RELEASE]
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1794) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:516) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:324) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:322) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:330) ~[spring-beans-5.2.9.RELEASE.jar:5.2.9.RELEASE]
... 33 common frames omitted
Caused by: org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:275) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:176) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:118) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1224) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1255) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:391) ~[spring-orm-5.2.9.RELEASE.jar:5.2.9.RELEASE]
at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264) ~[na:na]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:835) ~[na:na]
Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:100) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:54) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:137) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263) ~[hibernate-core-5.4.21.Final.jar:5.4.21.Final]
... 18 common frames omitted
Disconnected from the target VM, address: '127.0.0.1:51941', transport: 'socket'
Process finished with exit code 0

It can be originated from different reasons.
Make sure there is not a connection issue between your server and
your DB(try telnet or tracepath etc).
It can be caused by some limitation in your OS like an open socket
limitation or excess the limit of the number of open files of a
process which may results Too many open files.
Also maybe there are some issues in your network and maybe you
need to increase retry attempts to create a connection by using of
maxReconnects:
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://${db.host}:${db.port}/${db.db}"/>
<property name="username" value="${db.username}"/>
<property name="password" value="${db.password}"/>
<property name="connectionProperties">
<props>
<prop key="allowMultiQueries">true</prop>
<prop key="useUnicode">yes</prop>
<prop key="characterEncoding">utf8</prop>
<prop key="autoReconnect">true</prop>
<prop key="failOverReadOnly">false</prop>
<prop key="maxReconnects">10</prop>
</props>
</property>
</bean>
Also, I recommend using the latest version of JDBC MySQL driver.