我有一个curl命令

curl -F 'client_id={client id}' \
-F 'client_secret={client secret}' \
-F 'code={temporary token}' \
-F 'grant_type=authorization_code' \
https://cloud.lightspeedapp.com/oauth/access_token.php

取自https://developers.lightspeedhq.com/retail/authentication/access-token/
我尝试用java中的jetty请求来调用这个api。

URIBuilder uriBuilder = new URIBuilder("https://cloud.lightspeedapp.com")
  .setPath("/oauth/access_token.php");

MultiPartContentProvider contentProvider = new MultiPartContentProvider();
contentProvider.addFieldPart("grant_type", new StringContentProvider("authorization_code"), null);
contentProvider.addFieldPart("client_id", new StringContentProvider(lightspeedRId), null);
contentProvider.addFieldPart("client_secret", new StringContentProvider(lightspeedRSecret), null);
contentProvider.addFieldPart("code", new StringContentProvider(temporaryToken), null);
contentProvider.close();

Request request = httpClient.POST(uriBuilder.build())
  .content(contentProvider)
  .header("Content-Type", "multipart/form-data");

但是，它不起作用。我完全不知所措，不知道我需要改变这里。
编辑：我也尝试了一个FormContentProvider，得到了同样的结果。

Fields fields = new Fields();
fields.put("grant_type", "authorization_code");
fields.put("client_id", lightspeedRId);
fields.put("client_secret", lightspeedRSecret);
fields.put("code",temporaryToken);
FormContentProvider contentProvider = new FormContentProvider(fields);