the request was rejected because no multipart boundary was found java

Question

I am developing a file upload functionality. for that I have a spring boot web service and client is angular.

Webservice:-

    @PostMapping(value = "/sendmails", headers = "content-type=multipart/*", consumes = "application/*")
    public ResponseEntity<String> sendEmails(@RequestParam("data") MultipartFile reapExcelDataFile) {
    
        return new ResponseEntity("Success", HttpStatus.OK);
    }

UI: -

postFile(fileToUpload: File): Observable<boolean> {
  const endpoint = 'http://localhost:8080/sendmails';
debugger;
  let config =  {headers: new  HttpHeaders({ 'Content-Type': 'multipart/form-data'})};
  const formData: FormData = new FormData();
  formData.append('data', fileToUpload);
  return this.httpClient.post(endpoint, formData, config)
    .pipe(map(() => { return true; }));
}

ERROR: -

2020-07-31 16:13:19.644 ERROR 13144 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.io.IOException: org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was found] with root cause

org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was found at org.apache.tomcat.util.http.fileupload.FileUploadBase$FileItemIteratorImpl.(FileUploadBase.java:834) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.tomcat.util.http.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:256) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:280) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.connector.Request.parseParts(Request.java:2881) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.connector.Request.parseParameters(Request.java:3214) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.connector.Request.getParameter(Request.java:1116) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.connector.RequestFacade.getParameter(RequestFacade.java:381) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:84) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) [tomcat-embed-core-9.0.21.jar:9.0.21] at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.21.jar:9.0.21] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_251] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_251] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.21.jar:9.0.21] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_251]

If I remove the file and give a string then the call is going. What might be the issue.

Answer 1

If you are using angular 15+ with restful spring api, I did encapsulated the file in FormData object and it worked :

 const formData = new FormData();
 formData.append("file", file, file.name);

return this.http.post<any>(`${env.apiUrl}/controllerUrl/uploadFile`, formData);

Answer 2

The problem is that I am setting the Content-Type by myself, let it be blank. Google Chrome will do it for me. The multipart Content-Type needs to know the file boundary, and when you remove the Content-Type, Postman will do it automagically for you.