RestTemplate: how to send multipart?

Question

I need to send request. It looks like this cURL request:

 curl --location --request POST 'http://127.0.0.1:8080/api/attachments'
--form 'data=@path/to/file/6C233C5F-B60D-41CA-86ED-A43C51FD7EED.png'

If to convert it to IDEA http request, it shall look like here:

POST http://127.0.0.1:8080/api/attachments
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: form-data; name="data"; filename="6C233C5F-B60D-41CA-86ED-A43C51FD7EED.png"

< path/to/file/6C233C5F-B60D-41CA-86ED-A43C51FD7EED.png
--WebAppBoundary--

Ok, but I need to send it with restTemplate . And it's desirable to use byte[] instead of file path. Please, help.

Answer 1

Here is my code fragment

        HttpEntity<?> entity;
        HttpHeaders headers = new HttpHeaders();
        Object requestBody;
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        requestBody = Base64.getDecoder().decode(base64EncodedData);

        entity = new HttpEntity<>(requestBody, headers);

        ResponseEntity response = getRestTemplate().exchange(
                serviceURL,
                HttpMethod.POST,
                entity,
                String.class
        );

You can read file content to byte array and send it the same way.