인프런 커뮤니티 질문&답변

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스프링 기반 REST API 개발

Rest Docs 관련 문의 드립니다

해결된 질문

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본 강의를 듣고 다른 프로젝트에 Rest Docs를 적용해보고 있는데, 적용 도중 몇가지 문의 사항이 있습니다.

1. List의 각 요소에 self 링크 넣는 방법

강의 내용중에 Page의 각 요소에 PageResourcesAssembler를 이용해서 self 링크를 넣는 내용이 있었는데, Page가 아닌 List로 리턴하는 메소드에서를 어떻게 구현해야 될까요?

2. Resource 클래스를 상속한 클래스의 리턴시 에러 발생

Resource 클래스를 상속해서 링크를 생성해주는 클래스를 만들었습니다. 그리고 그 클래스를 리턴하게 했는데, 테스트에서는 통과가 되는데 실제 API 호출을 할 때는 에러가 발생합니다. 어떤 부분이 문제인지 문의드립니다.

<에러 내용>

org.springframework.http.converter.HttpMessageConversionException: Could not instantiate JAXBContext for class [class link.myrecipes.api.common.RestResource]: Implementation of JAXB-API has not been found on module path or classpath.; nested exception is javax.xml.bind.JAXBException: Implementation of JAXB-API has not been found on module path or classpath.

 - with linked exception:

[java.lang.ClassNotFoundException: com.sun.xml.internal.bind.v2.ContextFactory]

 at org.springframework.http.converter.xml.AbstractJaxb2HttpMessageConverter.getJaxbContext(AbstractJaxb2HttpMessageConverter.java:117) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.http.converter.xml.AbstractJaxb2HttpMessageConverter.createMarshaller(AbstractJaxb2HttpMessageConverter.java:51) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter.writeToResult(Jaxb2RootElementHttpMessageConverter.java:180) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.http.converter.xml.AbstractXmlHttpMessageConverter.writeInternal(AbstractXmlHttpMessageConverter.java:84) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:227) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:293) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:225) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:122) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:118) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 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 org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

Caused by: javax.xml.bind.JAXBException: Implementation of JAXB-API has not been found on module path or classpath.

 at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:278) ~[jaxb-api-2.3.1.jar:2.3.0]

 at javax.xml.bind.ContextFinder.find(ContextFinder.java:421) ~[jaxb-api-2.3.1.jar:2.3.0]

 at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:721) ~[jaxb-api-2.3.1.jar:2.3.0]

 at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:662) ~[jaxb-api-2.3.1.jar:2.3.0]

 at org.springframework.http.converter.xml.AbstractJaxb2HttpMessageConverter.getJaxbContext(AbstractJaxb2HttpMessageConverter.java:112) ~[spring-web-5.1.9.RELEASE.jar:5.1.9.RELEASE]

 ... 55 common frames omitted

Caused by: java.lang.ClassNotFoundException: com.sun.xml.internal.bind.v2.ContextFactory

 at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadClass(TomcatEmbeddedWebappClassLoader.java:68) ~[spring-boot-2.1.7.RELEASE.jar:2.1.7.RELEASE]

 at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188) ~[tomcat-embed-core-9.0.22.jar:9.0.22]

 at javax.xml.bind.ServiceLoaderUtil.nullSafeLoadClass(ServiceLoaderUtil.java:122) ~[jaxb-api-2.3.1.jar:2.3.0]

 at javax.xml.bind.ServiceLoaderUtil.safeLoadClass(ServiceLoaderUtil.java:155) ~[jaxb-api-2.3.1.jar:2.3.0]

 at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:276) ~[jaxb-api-2.3.1.jar:2.3.0]

 ... 59 common frames omitted

<클래스 코드>

public class RestResource<T> extends Resource<T> {
    public RestResource(T content, String key, Class<?> controllerClass, LinkType[] addLinks, String linkPrefix, Link... links) {
        super(content, links);
        add(linkTo(controllerClass).slash(key).withSelfRel());

        List<LinkType> addLinkList = Arrays.asList(addLinks);
        if (addLinkList.contains(LinkType.CREATE)) {
            add(linkTo(controllerClass).withRel(linkPrefix + "-create"));
        }
        if (addLinkList.contains(LinkType.READ)) {
            add(linkTo(controllerClass).withRel(linkPrefix + "-read"));
        }
        if (addLinkList.contains(LinkType.UPDATE)) {
            add(linkTo(controllerClass).withRel(linkPrefix + "-update"));
        }
        if (addLinkList.contains(LinkType.DELETE)) {
            add(linkTo(controllerClass).withRel(linkPrefix + "-delete"));
        }
        if (addLinkList.contains(LinkType.QUERY)) {
            add(linkTo(controllerClass).withRel(linkPrefix + "-query"));
        }
    }

    public RestResource(T content, Link... links) {
        super(content, links);
    }

    public void addProfileLink(String profileLink) {
        add(new Link(profileLink).withRel("profile"));
    }

    public Link selfLink() {
        return getLinks("self").get(0);
    }
}

springjavarest-api

답변 2

0

mycat님의 프로필 이미지
mycat
질문자

브라우저에서 API 요청을 할 경우 Accept 헤더를 생각하지 못했던것 같네요. Postman을 사용하여 정상 응답을 받았습니다.

1번같은 경우는 Page의 사용을 고려해봐야 할 것 같습니다.

답변 감사드립니다^^

0

백기선님의 프로필 이미지
백기선
지식공유자

1. Resouece를 List 만들고 Resource에 링크를 넣어주시면 가능하겠지만 일반 도메인 클래스의 List에는 링크를 넣어줄 곳이 없네요.

2. 요청을 웹 브라우저에서 하는 경우, 원하는 응답 타입으로 XML, HTML이 Accept 헤더에 들어갈겁니다. (기본으로) 그래서 XML로 응답을 만들어 주려고 하다보니 XML 관련 라이브러리를 찾고 있는데 그게 없어서 에러가 나고 있는거네요. 웹브라우저 말고 Postman이나 REST Client를 사용해서 Accept 헤더에 JSON으로 받겠다고 설정하고 보내보시면 잘 될겁니다. XML로 받고 싶으시면 에러메시지에서  없다고 하는 클래스 담고 있는 라이브러리를 의존성을 추가하시면 되구요.

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