今天在项目中写了一个下载功能，报出了这样的错误信息：

org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation

at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:287)

at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:182)

at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)

at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:870)

at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:776)

at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)

at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)

at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)

at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)

at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:870)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)

at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:855)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:96)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at com.guazi.aftermarket.eims.graphql.filter.CorsFilter.doFilter(CorsFilter.java:34)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158)

at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126)

at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:84)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)

at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)

at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)

at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)

at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)

at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)

at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:748)

经过面向google编程，发现可能出发这种异常情况的原因：

第一：

请求contenttype=application/json;charset=UTF-8,而这里的produces=text/html

原来代码：

@RequestMapping(value = “/upload”, method = RequestMethod.POST, produces = “text/html; charset=UTF-8”)

解决方法：去掉produces = “text/html; charset=UTF-8″这段代码或者设置produces=application/json;charset=UTF-8

查看自己代码：

发现调用controller如下：

请求信息

在produces中的设置为静态变量：MediaType.APPLICATION_JSON_UTF8_VALUE，查看静态变量如下：

静态变量

与通用解释一致，不是同样的问题。

第二：方法名重复

例子：

① html的名字   showArticle.html

② js的名字   showArticle.js

③ajax传到后台来执行的方法名   ajax的url:”showArticle”

④后台拦截方法名

@ResponseBody

@RequestMapping(value = “/showArticle”, method = RequestMethod.POST)

解决方案

防止静态文件名跟控制器请求路由冲突。如本例中，将login.html更名为signin.html。

将静态文件URI与动态请求URI分离。如，把提供REST接口的URI都改成以/api/XXX开头，把静态文件改为以/static/XXX开头。这样当请求/static/login.html时，spring会直接使用内置的处理静态资源的控制器返回静态文件而不再去查找用户定义的控制器（此解释引用自博客）

但是修改自己的方法名还是会报相同的错误信息，因此排除此种可能

第三：自己debug查看具体情况

此问题是由切面捕获到的异常信息，切面如下：

异常处理

怀疑是：handler处理时发生异常。

debug进入后，发现抛异常发生在：

抛异常代码

由此看出，在不应该有outputValue的情况下又返回，造成了此问题。

看一下controller：

controller方法

确实写了返回值，与报错一致，因此将返回改成void。

改了代码后，正常了！