in context with path [] threw exception [java.lang.NullPointerException] with root cause

ERROR 내용

`11월 13, 2023 4:36:40 오후 org.apache.catalina.core.ContainerBase startInternal
심각: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]]
at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:892)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:793)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1362) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1352)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:829) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ... 6 more Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4940) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 6 more Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:527)
... 11 more

11월 13, 2023 4:36:40 오후 org.apache.catalina.core.ContainerBase startInternal
심각: 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)
at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:892)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:252)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:429)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:778)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:440)
at org.example.WebApplicationServer.main(WebApplicationServer.java:21)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:904)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:793)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1362) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1352)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:829) Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]] at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:892) ... 8 more Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ... 6 more Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4940) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 6 more Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:527)
... 11 more

Exception in thread "main" org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:904)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:252)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:429)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:778)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:440)
at org.example.WebApplicationServer.main(WebApplicationServer.java:21)
Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: A child container failed during start
at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122)
at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:892)
... 8 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:904)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:793)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1362) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1352)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:829) Caused by: java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]] at java.base/java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:191) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:892) ... 8 more Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[]] at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198) ... 6 more Caused by: java.lang.NoClassDefFoundError: org/apache/tomcat/util/descriptor/tld/TldParser at org.apache.jasper.servlet.TldScanner.<init>(TldScanner.java:84) at org.apache.jasper.servlet.JasperInitializer.newTldScanner(JasperInitializer.java:118) at org.apache.jasper.servlet.JasperInitializer.onStartup(JasperInitializer.java:99) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:4940) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ... 6 more Caused by: java.lang.ClassNotFoundException: org.apache.tomcat.util.descriptor.tld.TldParser at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:527)
... 11 more

Process finished with exit code 1
`

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [java.lang.NullPointerException] with root cause

상황

어제까지 잘 되었는데 왜 갑자기 안되지....

복잡한 것도 아니고 기초를 하는데........

의존성 문제인가 해서 의존성 지웠다가 다시 설치

경로도 고쳤다가.. /을 붙였다가 안붙였다가...

결국 고쳤따!

---

다음날 또 같은 에러가 나왔따....
의존성을 지웠다가 다시 설치했다가.. 위 경로가 바뀌어서 또 다시 수정하다보니 에러가 사라졌다. 대체 뭐지..?

해결 방법

왜 그런건지는 모르겠지만, project structure>Modules>main>Compiler Output>User module compile output path의 output path가 처음 상태로 돌아가 있었다.

이 부분을

(project명)\webapps WEB-INF\classes
로 고치니까 해결됨!!!

추가로, jsp 파일 찾아갈 때 앞에 \ 반드시 해줘야 한다.
이 부분도 Null에러가 뜬다(당연하지.. 경로에 없으니까...~!)