ControllerAdvice ResponseBodyAdviceが文字列レスポンスを囲みませんでした

Question

理由はわかりませんが、エンドポイントがStringを返すと、ResponseBodyAdviceは常にCasting例外をスローします。 Long、Listなどの他のデータ型は必要に応じて機能し、Stringデータだけが例外になりました。どのようにこの問題を解決するための任意の提案？ここ

@RestController 
public class AppController { 
    private static Logger logger = LogManager.getLogger(AppController.class); 

    @RequestMapping(path = "/hello", 
        method = GET) 
    public String hello() { 
     logger.info("... AppController.hello()"); 

     return "hello, world!"; 
    } 

    @RequestMapping(path = "/timestamp", 
        method = GET) 
    public long timestamp() { 
     logger.info("... AppController.timestamp()"); 
     return System.currentTimeMillis(); 
    } 
} 

が顧問である：

：

@ControllerAdvice 
public class ResponseAdviser implements ResponseBodyAdvice<Object> { 
    private static Logger logger = LogManager.getLogger(ResponseAdviser.class); 

    @Override 
    public boolean supports(MethodParameter returnType, 
          Class<? extends HttpMessageConverter<?>> converterType) { 
     logger.trace("... ResponseAdviser.supports()"); 

     return true; 
    } 

    @Override 
    public Object beforeBodyWrite(Object body, 
            MethodParameter returnType, 
            MediaType selectedContentType, 
            Class<? extends HttpMessageConverter<?>> selectedConverterType, 
            ServerHttpRequest request, 
            ServerHttpResponse response) { 
     logger.info("... ResponseAdviser.beforeBodyWrite()"); 

     Response resp = new Response(); 
     resp.setData(body); 

     return resp; 
    } 
} 

そしてREPONSEクラスは基本的に、タイムスタンプを追加し、エンドポイントを囲みここ

@Data 
public class Response { 
    private Date timestamp; 
    private Object data; 

    public Response() { 
     this.timestamp = new Date(); 
    } 
} 

は、スタックトレースでデータを返さ

Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: org.phan.message.Response cannot be cast to java.lang.String] with root cause 

java.lang.ClassCastException: org.phan.message.Response cannot be cast to java.lang.String 
    at org.springframework.http.converter.StringHttpMessageConverter.getContentLength(StringHttpMessageConverter.java:41) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.http.converter.AbstractHttpMessageConverter.addDefaultHeaders(AbstractHttpMessageConverter.java:260) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:205) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:247) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:174) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:113) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:110) ~[spring-boot-actuator-1.5.3.RELEASE.jar:1.5.3.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:106) ~[spring-boot-actuator-1.5.3.RELEASE.jar:1.5.3.RELEASE] 
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.8.RELEASE.jar:4.3.8.RELEASE] 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_121] 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_121] 
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.14.jar:8.5.14] 
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121] 

Answer 1

を解決することがありますが、以下のコードを試すことができます。

@Configuration 
public class WebConfig extends WebMvcConfigurerAdapter { 

    @Override 
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { 

     super.configureMessageConverters(converters); 
     converters.add(0, new MappingJackson2HttpMessageConverter()); 
    } 
} 

Answer 2

S残りのエンドポイントを識別するために@RestController注釈を使用しています。Adviceを添付する場合は、残りのエンドポイント用に設計された@RestControllerAdvice注釈を使用する必要があります。

Answer 3

このエラーは、beforeBodyWriteメソッドとrequestmappingメソッドの戻り値の型が同じである必要があるために発生します。コントローラ内の応答を常に返すようにしてください。

他のすべてのタイプのfastJsonまたはjavabeanは、文字列以外のエラーはありません。そこで、String型を処理するための追加コードを記述します。 ResponseのtoString()を上書きし、次のタイプがStringの場合はResponse.toString()を返します。これはあなたの問題