I am new to Java (Spring Boot), and i am trying to send a multipart/form-data
POST request to s3 to upload a file.
I managed to do this using spring's RestTemplate
like this :
public String uploadFile(byte[] file, Map<String, Object> fields, String url) throws URISyntaxException {
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART_FORM_DATA);
MultiValueMap<String, Object> formData= new LinkedMultiValueMap<String, Object>();
for (Map.Entry<String, Object> entry : fields.entrySet()) {
formData.add(entry.getKey(), entry.getValue());
}
formData.add("file", file);
HttpEntity<MultiValueMap<String, Object>> request = new HttpEntity<MultiValueMap<String, Object>>(formData, headers);
String response = restTemplate.postForObject(new URI(url), request, String.class);
return response;
}
Then i tried to do the same using webclient
, but i can not and AWS respond with The body of your POST request is not well-formed multipart/form-data.
Here is the code using webclient :
public String uploadFileWebc(byte[] file, Map<String, Object> fields, String url) {
MultipartBodyBuilder builder = new MultipartBodyBuilder();
for (Map.Entry<String, Object> entry : fields.entrySet()) {
builder.part(entry.getKey(), entry.getValue(), MediaType.TEXT_PLAIN);
}
builder.part("file", file).filename("file");
MultiValueMap<String, HttpEntity<?>> parts = builder.build();
Void result = webClient.filter(errorHandlingFilter()).build().post().uri(url)
.contentType(MediaType.MULTIPART_FORM_DATA)
.contentLength(file.length)
.bodyValue(parts)
.retrieve()
.bodyToMono(Void.class)
.block();
return "Done Uploading.";
}
Can anybody please point out what am i missing ?
It turns out that webclient
does not add the content-length
header due to its streaming nature, and S3 API needs this header to be sent.
I ended up using restTemplate
for uploading files to S3.