Spring Boot curl example with multipart/form-data and JSON metadata in POST request

Below are two curl examples of Spring Boot controller method signatures for a multipart/form-data POST request, one with request parameter metadata, one with JSON request body metadata.

Environment:
Spring Boot / Spring Boot Starter Batch Version 1.5.6.RELEASE
Oracle Java 8

1. multipart/form-data POST request with request parameter metadata

curl:
curl -k -H 'Content-Type: multipart/form-data' -F 'docFiles=@test1.txt;type=text/plain' 'https://localhost:8443/cherryshoe-app/document/file/upload/REVIEW?id=3554&docTypeId=1'

-k is to  to turn off curl's verification of the self-signed certificate
-F Contents to be read from file use the @

Matching Java Controller Method Signature:

@RequestMapping(value = "/document/file/upload", consumes = "multipart/form-data", produces = "application/json;charset=utf-8", method = RequestMethod.POST)

@ResponseBody
public DocumentUploadMetadata fileUpload(
    @RequestParam(value = "id", required = true) final Long reviewId,
    @RequestParam(value = "docTypeId", required = true) final Long docTypeId,
    @RequestParam("docFiles") List<MultipartFile> docFiles, Principal principal)
    throws IllegalArgumentException, NullPointerException, Exception {
}

2. multipart/form-data POST request with JSON request body metadata

curl:
curl -k -H 'Content-Type: multipart/form-data' -F 'docFiles=@test1.txt;type=text/plain' -F metadata='{"reviewId":3554,"docTypeId":1,"customFileName":"customFileName.txt","commentText":"This is a really long text, it may even be in HTML"};type=application/json' 'https://localhost:8443/cherryshoe-app/document/file/upload'

-k is to  to turn off curl's verification of the self-signed certificate
-F Contents to be read from file use the @

Matching Java Controller Method Signature:

@RequestMapping(value = "/document/file/upload", consumes = "multipart/form-data", produces = "application/json;charset=utf-8", method = RequestMethod.POST)

@ResponseBody
public DocumentUploadMetadata fileUpload(@RequestPart("docFiles") List<MultipartFile> docFiles,
    @RequestPart("metadata") DocumentUploadMetadata metadata, Principal principal)
    throws IllegalArgumentException, NullPointerException, Exception {
}

This Signature also works, had to do this to work with ng-file-upload library:

/**
 * Takes a list of document MultipartFile's, and JSON metadata.
 * 
 * NOTE: To make this work with ng-file-upload: - have to pass the JSON
 * metadata as a String, and then deserialize the JSON String manually in
 * the controller.
 * 
 * @param docFiles
 * @param metadata
 * @param principal
 * @return
 * @throws IllegalArgumentException
 * @throws NullPointerException
 * @throws Exception
 */
@RequestMapping(value = "/document/file/upload", consumes = "multipart/form-data", produces = "application/json;charset=utf-8", method = RequestMethod.POST)
@ResponseBody
public DocumentUploadMetadata fileUpload(@RequestParam("docFiles") List<MultipartFile> docFiles,
        @RequestParam("metadata") String metadataJson, Principal principal)
        throws IllegalArgumentException, NullPointerException, Exception {
  // deserialize metadataJson JSON string manually
}

POJO for JSON metadata serialization/deserialization:

public class DocumentUploadMetadata {
    private Long reviewId;
    private Long docTypeId;
    private String customFileName;
    private String commentText;

    public DocumentUploadMetadata() {
        super();
    }
    
    // getters and setters are needed for jackson serialization/deserialization, add them for this to work
}

Helpful curl documentation: https://curl.haxx.se/docs/manual.html