InvalidDefinitionException

나의 프로젝트 시작 후 REST API를 만드는 과정에서의 첫 에러 등장!

 

에러 내용:

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class com.hotelJava.accommodation.dto.AccommodationResponseDTO and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) (through reference chain: java.util.ArrayList[0])
	at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:77) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.SerializerProvider.reportBadDefinition(SerializerProvider.java:1306) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.DatabindContext.reportBadDefinition(DatabindContext.java:408) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.failForEmpty(UnknownSerializer.java:53) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.impl.UnknownSerializer.serialize(UnknownSerializer.java:30) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:145) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:107) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:400) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1568) ~[jackson-databind-2.14.2.jar:2.14.2]
	at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:1061) ~[jackson-databind-2.14.2.jar:2.14.2]
	at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:483) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:103) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:297) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:194) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:78) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:135) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:705) ~[tomcat-embed-core-10.1.5.jar:6.0]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.5.jar:6.0.5]
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:814) ~[tomcat-embed-core-10.1.5.jar:6.0]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:223) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.5.jar:6.0.5]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.5.jar:6.0.5]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.5.jar:6.0.5]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.5.jar:6.0.5]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:185) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:158) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:177) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:119) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:400) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:859) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1734) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-10.1.5.jar:10.1.5]
	at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

 

에러 원인: @ResponseBody로 DTO를 리턴 시킬때 발생한 에러이며 JSON으로 파싱하기 위해 사용하는 Jackson이 DTO의 값을 읽어올 수 있어야하는데 DTO.java에 @Getter를 선언하지 않았었다...

 

해결 방법: DTO.java 파일에 @Getter 애노테이션 선언