Spring Resttemplate : how to post file and common String data at the same time

I meet a request to upload files with spring resttemplate to upload files with http header "multipart/form-data", also some other normal parameters need to be posted. how to implements that?

You can use the following code in your application to have both multipart-file and normal request parameters at the same time:

Note:

• replace the URL with your own
• replace parameter names and values according to your normal parameters

String url = "http://example.com";
String fileAbsPath = "absolute path of your file";
String fileName = new File(fileAbsPath).getName();

Files.readAllBytes(Paths.get(fileAbsPath));

MultiValueMap<String, Object> data = new LinkedMultiValueMap<String, Object>();

ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(Paths.get(fileAbsPath))) {
    @Override
    public String getFilename() {
        return fileName;
    }
};

data.add("file", resource);

HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("file","application/pdf");

UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(url)
    .queryParam("param1", "value1")
    .queryParam("param2", "value2");

HttpEntity<> entity = new HttpEntity<> (data, requestHeaders);

RestTemplate restTemplate = new RestTemplate();

ResponseEntity<String> result =restTemplate.exchange(
    builder.toUriString(),
    HttpMethod.POST,
    entity,
    String.class
);

System.out.println(result.getBody());