Multipart File Upload Using Spring Rest Template + Spring Web MVC

I am trying to upload a File using RestTemplate with the following code.

   MultiValueMap<String, Object> multipartMap = new LinkedMultiValueMap<>();
   multipartMap.add("file", new ClassPathResource(file));

   HttpHeaders headers = new HttpHeaders();
   headers.setContentType(new MediaType("multipart", "form-data"));

   HttpEntity<MultiValueMap<String, Object>> request = new HttpEntity<MultiValueMap<String, Object>>(multipartMap, headers);

   System.out.println("Request for File Upload : " + request);

   ResponseEntity<byte[]> result = template.get().exchange(
					contextPath.get() + path, HttpMethod.POST, request,
					byte[].class);

I have the MultipartResolver bean and Controller code is

@RequestMapping(value = "/{id}/image", method = RequestMethod.POST)
@ResponseStatus(HttpStatus.NO_CONTENT)
@Transactional(rollbackFor = Exception.class)
public byte[] setImage(@PathVariable("id") Long userId,
		@RequestParam("file") MultipartFile file) throws IOException {
	// Upload logic
}

And I get the following Exception

 org.springframework.web.bind.MissingServletRequestParameterException: Required MultipartFile parameter 'file' is not present
    	at org.springframework.web.method.annotation.RequestParamMethodArgumentResolver.handleMissingValue(RequestParamMethodArgumentResolver.java:255) ~[spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver.resolveArgument(AbstractNamedValueMethodArgumentResolver.java:95) ~[spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:79) ~[spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:157) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:124) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:646) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) [spring-webmvc-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.springframework.web.filter.ShallowEtagHeaderFilter.doFilterInternal(ShallowEtagHeaderFilter.java:80) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:67) [log4j-web-2.0.2.jar:2.0.2]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at m.m.m.AbstractPreAuthenticatedProcessingFilter.doFilter(UapAbstractPreAuthenticatedProcessingFilter.java:109) [classes/:?]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.2.5.RELEASE.jar:3.2.5.RELEASE]
    	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261) [spring-web-4.0.6.RELEASE.jar:4.0.6.RELEASE]
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [?:1.7.0_67]
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [?:1.7.0_67]
    	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-7.0.54.jar:7.0.54]
    	at java.lang.Thread.run(Thread.java:745) [?:1.7.0_67]

The Multipart File Upload worked after following code modification to Upload using RestTemplate

LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
map.add("file", new ClassPathResource(file));
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);

HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new    HttpEntity<LinkedMultiValueMap<String, Object>>(
    				map, headers);
ResponseEntity<String> result = template.get().exchange(
					contextPath.get() + path, HttpMethod.POST, requestEntity,
					String.class);

And adding MultipartFilter to web.xml

    <filter>
		<filter-name>multipartFilter</filter-name>
		<filter-class>org.springframework.web.multipart.support.MultipartFilter</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>multipartFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

For most use cases, it's not correct to register MultipartFilter in web.xml because Spring MVC already does the work of processing your multipart request. It's even written in the filter's javadoc.

On the server side, define a multipartResolver bean in your app context:

@Bean
public CommonsMultipartResolver multipartResolver(){
    CommonsMultipartResolver commonsMultipartResolver = new CommonsMultipartResolver();
    commonsMultipartResolver.setDefaultEncoding("utf-8");
    commonsMultipartResolver.setMaxUploadSize(50000000);
    return commonsMultipartResolver;
}

On the client side, here's how to prepare the request for use with Spring RestTemplate API:

	HttpHeaders headers = new HttpHeaders();
	headers.setContentType(MediaType.MULTIPART_FORM_DATA);

	LinkedMultiValueMap<String, String> pdfHeaderMap = new LinkedMultiValueMap<>();
	pdfHeaderMap.add("Content-disposition", "form-data; name=filex; filename=" + file.getOriginalFilename());
	pdfHeaderMap.add("Content-type", "application/pdf");
	HttpEntity<byte[]> doc = new HttpEntity<byte[]>(file.getBytes(), pdfHeaderMap);

	LinkedMultiValueMap<String, Object> multipartReqMap = new LinkedMultiValueMap<>();
	multipartReqMap.add("filex", doc);

	HttpEntity<LinkedMultiValueMap<String, Object>> reqEntity = new HttpEntity<>(multipartReqMap, headers);
	ResponseEntity<MyResponse> resE = restTemplate.exchange(uri, HttpMethod.POST, reqEntity, MyResponse.class);

The important thing is really to provide a Content-disposition header using the exact case, and adding name and filename specifiers, otherwise your part will be discarded by the multipart resolver.

Then, your controller method can handle the uploaded file with the following argument:

@RequestParam("filex") MultipartFile file

Hope this helps.

Here are my working example

@RequestMapping(value = "/api/v1/files/upload", method =RequestMethod.POST)
public ResponseEntity<?> upload(@RequestParam("files") MultipartFile[] files) {
    LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
    List<String> tempFileNames = new ArrayList<>();
    String tempFileName;
    FileOutputStream fo;

    try {
        for (MultipartFile file : files) {
            tempFileName = "/tmp/" + file.getOriginalFilename();
            tempFileNames.add(tempFileName);
            fo = new FileOutputStream(tempFileName);
            fo.write(file.getBytes());
            fo.close();
            map.add("files", new FileSystemResource(tempFileName));
        }

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);

        HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new HttpEntity<>(map, headers);
        String response = restTemplate.postForObject(uploadFilesUrl, requestEntity, String.class);

    } catch (IOException e) {
        e.printStackTrace();
    }

    for (String fileName : tempFileNames) {
        File f = new File(fileName);
        f.delete();
    }
    return new ResponseEntity<Object>(HttpStatus.OK);
}

For those who are getting the error as:

I/O error on POST request for "anothermachine:31112/url/path";: class path 
resource [fileName.csv] cannot be resolved to URL because it does not exist.

It can be resolved by using the

LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
map.add("file", new FileSystemResource(file));

If the file is not present in the classpath, and an absolute path is required.

A correct file upload would like this:

HTTP header:

> Content-Type: multipart/form-data; boundary=ABCDEFGHIJKLMNOPQ

Http body:

> --ABCDEFGHIJKLMNOPQ > > Content-Disposition: form-data; name="file"; filename="my.txt" > > Content-Type: application/octet-stream > > Content-Length: ... > > <...file data in base 64...> > > --ABCDEFGHIJKLMNOPQ--

and code is like this:

public void uploadFile(File file) {
        try {
            RestTemplate restTemplate = new RestTemplate();
            String url = "http://localhost:8080/file/user/upload";
            HttpMethod requestMethod = HttpMethod.POST;

            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.MULTIPART_FORM_DATA);


            MultiValueMap<String, String> fileMap = new LinkedMultiValueMap<>();
            ContentDisposition contentDisposition = ContentDisposition
                    .builder("form-data")
                    .name("file")
                    .filename(file.getName())
                    .build();

            fileMap.add(HttpHeaders.CONTENT_DISPOSITION, contentDisposition.toString());
            HttpEntity<byte[]> fileEntity = new HttpEntity<>(Files.readAllBytes(file.toPath()), fileMap);

            MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
            body.add("file", fileEntity);

            HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);

            ResponseEntity<String> response = restTemplate.exchange(url, requestMethod, requestEntity, String.class);

            System.out.println("file upload status code: " + response.getStatusCode());

        } catch (IOException e) {
            e.printStackTrace();
        }

}

More based on the feeling, but this is the error you would get if you missed to declare a bean in the context configuration, so try adding

<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="maxUploadSize" value="10000000"/>
</bean>