TroubleShooting

발생한 문제

GlobalExceptionHandler 를 작성중에 다음과 같이 작성중에 아래 와 같은 Bean creation 문제가 터졌다.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'handlerExceptionResolver' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Failed to instantiate [org.springframework.web.servlet.HandlerExceptionResolver]: Factory method 'handlerExceptionResolver' threw exception with message: Ambiguous @ExceptionHandler method mapped for [class org.springframework.web.bind.MethodArgumentNotValidException]: {public org.springframework.http.ResponseEntity xyz.moveuk.post.global.exception.GlobalExceptionHandler.handleMethodArgumentNotValidException(org.springframework.web.bind.MethodArgumentNotValidException), public final org.springframework.http.ResponseEntity org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler.handleException(java.lang.Exception,org.springframework.web.context.request.WebRequest) throws java.lang.Exception}
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:651) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:639) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1164) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:561) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:975) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:959) ~[spring-context-6.1.3.jar:6.1.3]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:624) ~[spring-context-6.1.3.jar:6.1.3]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.2.2.jar:3.2.2]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754) ~[spring-boot-3.2.2.jar:3.2.2]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456) ~[spring-boot-3.2.2.jar:3.2.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:334) ~[spring-boot-3.2.2.jar:3.2.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1354) ~[spring-boot-3.2.2.jar:3.2.2]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343) ~[spring-boot-3.2.2.jar:3.2.2]
	at xyz.moveuk.post.PostApplicationKt.main(PostApplication.kt:15) ~[main/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.web.servlet.HandlerExceptionResolver]: Factory method 'handlerExceptionResolver' threw exception with message: Ambiguous @ExceptionHandler method mapped for [class org.springframework.web.bind.MethodArgumentNotValidException]: {public org.springframework.http.ResponseEntity xyz.moveuk.post.global.exception.GlobalExceptionHandler.handleMethodArgumentNotValidException(org.springframework.web.bind.MethodArgumentNotValidException), public final org.springframework.http.ResponseEntity org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler.handleException(java.lang.Exception,org.springframework.web.context.request.WebRequest) throws java.lang.Exception}
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:177) ~[spring-beans-6.1.3.jar:6.1.3]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:647) ~[spring-beans-6.1.3.jar:6.1.3]
	... 19 common frames omitted
Caused by: java.lang.IllegalStateException: Ambiguous @ExceptionHandler method mapped for [class org.springframework.web.bind.MethodArgumentNotValidException]: {public org.springframework.http.ResponseEntity xyz.moveuk.post.global.exception.GlobalExceptionHandler.handleMethodArgumentNotValidException(org.springframework.web.bind.MethodArgumentNotValidException), public final org.springframework.http.ResponseEntity org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler.handleException(java.lang.Exception,org.springframework.web.context.request.WebRequest) throws java.lang.Exception}
	at org.springframework.web.method.annotation.ExceptionHandlerMethodResolver.addExceptionMapping(ExceptionHandlerMethodResolver.java:114) ~[spring-web-6.1.3.jar:6.1.3]
	at org.springframework.web.method.annotation.ExceptionHandlerMethodResolver.<init>(ExceptionHandlerMethodResolver.java:78) ~[spring-web-6.1.3.jar:6.1.3]
	at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.initExceptionHandlerAdviceCache(ExceptionHandlerExceptionResolver.java:289) ~[spring-webmvc-6.1.3.jar:6.1.3]
	at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.afterPropertiesSet(ExceptionHandlerExceptionResolver.java:256) ~[spring-webmvc-6.1.3.jar:6.1.3]
	at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.addDefaultHandlerExceptionResolvers(WebMvcConfigurationSupport.java:1063) ~[spring-webmvc-6.1.3.jar:6.1.3]
	at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.handlerExceptionResolver(WebMvcConfigurationSupport.java:1005) ~[spring-webmvc-6.1.3.jar:6.1.3]
	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.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:140) ~[spring-beans-6.1.3.jar:6.1.3]
	... 20 common frames omitted

해결 및 시도 방법

MethodArgumentNotValidException 은 이미 내가 상속받은 ResponseEntityExceptionHandler 추상클래스에서 처리중인 것을 인지했다. 아래처럼 ctrl + o 를 누르게 되면 override 창에서 관련 메소드가 있는 것을 확인할 수 있다.

기존에 처리하던게 있는데 내가 그것을 덮어버리니 알맞게 @ExceptionHandler 연결되지 않아 빈이 생성되지 않았던 것 같았다.

Ambiguous @ExceptionHandler method mapped for [class org.springframework.web.bind.MethodArgumentNotValidException]

콘솔 오류메세지에서도 확인할 수 있듯 모호한 메서드 매핑이 문제였던 것.

따라서 기존에 내가 작성했던 메소드를 없애고 이 메소드를 오버라이드 하여 구현해주었다.

세부사항 변화

기존

직접 작성한 MethodArgumentNotValidException 핸들링 메서드

수정

오버라이드하여 작성한 MethodArgumentNotValidException 핸들링 메서드

회고

ResponseEntityExceptionHandler 를 사용한다는 것은 스프링이 기존에 관리하던 Exception을 이어받아 처리해주겠다는 것인데 그것을 간과하고 바로 핸들링을 위한 메서드를 만들어주었기 때문에 이런 문제가 생긴 것 같다.

다음부터는 어떤 문제가 발생할 수 있는지 객체를 사용하기 전에 생각해보는 습관을 들여야 할 것 같다.