Spring Boot Unsupported Media Type 415 Content type '' not supported for request with empty parameters

Question

I have following rest controller RestController.class:

@AllArgsConstructor
@RestController
@RequestMapping(value = "/foo", produces = APPLICATION_JSON_VALUE)
@Api(value = "restController ")
class RestController {
    private final Service service;

    @PostMapping(value = "/foo", consumes = {MULTIPART_FORM_DATA_VALUE})
    public ResponseDTO foo(
            @ModelAttribute RequestDTO dto
    ) {
        return service.foo(dto);
    }

}

and request dto RequestDTO.class:

@Data
@NoArgsConstructor
@AllArgsConstructor
public class RequestDTO {
    private MultipartFile file;
    private SomeOtherObject someOtherObject;
}

The problem is when I send a request with no given parameters I receives in logs: .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type '' not supported]

and as response:

{
  "timestamp": 1677747390307,
  "status": 415,
  "error": "Unsupported Media Type",
  "trace": "org.springframework.web.HttpMediaTypeNotSupportedException: Content type '' not supported\r\n\tat org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.handleNoMatch(RequestMappingInfoHandlerMapping.java:267)\r\n\tat org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lookupHandlerMethod(AbstractHandlerMethodMapping.java:442)\r\n\tat org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:383)\r\n\tat org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getHandlerInternal(RequestMappingInfoHandlerMapping.java:125)\r\n\tat org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getHandlerInternal(RequestMappingInfoHandlerMapping.java:67)\r\n\tat org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:498)\r\n\tat org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1265)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1047)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:964)\r\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\r\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:681)\r\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:764)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\r\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\r\n\tat org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:96)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\r\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)\r\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)\r\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)\r\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)\r\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)\r\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\r\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)\r\n\tat org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)\r\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360)\r\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399)\r\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\r\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890)\r\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789)\r\n\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\r\n\tat org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)\r\n\tat org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)\r\n\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\r\n\tat 

I would like to proceed even those parameters are missing, because I want to make a validation and return a proper message when e.g. field file in RequestDTO.class is missing, but it is not possible due to mentioned exception behined the scenes in spring.

I'm using spring:

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.4</version>
        <relativePath/>
    </parent>

I have tried to use other media types.

I do not want to handle that exception, because this seems to be not correct way. I do not want to use @RequestBody in that case, it have to be a @ModelAttribute

Answer 1

To make the API endpoint can bind the upload file to MultipartFile without specifying its Content-Type in the HTTP request header as multipart/form-data , you first have to change the @PostMapping 's consumes to :

@PostMapping(value = "/foo")
public ResponseDTO foo(@ModelAttribute RequestDTO dto) {
        
}

Second, you also need to customize MultipartResolver because the default StandardServletMultipartResolver which only consider a HTTP request as the multipart request if its Content-Type is multipart/form-data. So also register the following beans :

@Bean(name = DispatcherServlet.MULTIPART_RESOLVER_BEAN_NAME)
public StandardServletMultipartResolver multipartResolver() {
    StandardServletMultipartResolver multipartResolver = new StandardServletMultipartResolver(){
        @Override
        public boolean isMultipart(HttpServletRequest request) {
            return true;
        }
    };
    return multipartResolver;
}

Answer 2

looks like a possible duplicate. find the approved comment from the mentioned link. this helped me. i believe this will also help you.

Spring cannot process “multipart/form-data” POST request (error 400 “Bad request”)