Spring Boot RestTemplate: Bad request when directly copying from postman - spring-boot

Question

So I have an API request where I am copying the details directly from postman where it works. I am however getting a bad request error.
#Service
public class GraphApiService {
#Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
#Autowired
RestTemplate restTemplate;
#Autowired
Constants constants;
private final Logger logger = LoggerFactory.getLogger(this.getClass());
public ResponseEntity<String> getAccessTokenUsingRefreshToken(Credential cred) throws IOException{
try {
//https://learn.microsoft.com/en-us/graph/auth-v2-user
// section 5. Use the refresh token to get a new access token
String url = "url";
JSONObject body = new JSONObject();
body.put("grant_type", "refresh_token");
body.put("client_id", "clientid");
body.put("scope","User.Read offline_access Files.Read Mail.Read Sites.Read.All");
body.put("redirect_uri", "http://localhost");
body.put("client_secret","secret");
body.put("refresh_token", "token");
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity<String> request = new HttpEntity<String>(body.toString(), headers);
ResponseEntity<String> response= restTemplate.postForEntity(url, request,String.class);
return response;
}
catch(HttpClientErrorException e){
logger.error(e.getResponseBodyAsString());
logger.error(e.getMessage());
return null;
}
}
I would appreciate any help. The bad request error message from microsoft graph isn't a descriptive one that will help

Answer 1

You're sending JSON payload with FORM_URLENCODED header.
Either you need to check if API accepts json payload, if so you need to change content-type to application/json or you can post form data as follows.
public ResponseEntity<String> getAccessTokenUsingRefreshToken(Credential cred) throws IOException{
try {
//https://learn.microsoft.com/en-us/graph/auth-v2-user
// section 5. Use the refresh token to get a new access token
String url = "url";
MultiValueMap<String, String> multiValueMap= new LinkedMultiValueMap<String, String>();
multiValueMap.add("grant_type", "refresh_token");
multiValueMap.add("client_id", "clientid");
//.....
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(multiValueMap, headers);
ResponseEntity<String> response= restTemplate.postForEntity(url, request, String.class);
return response;
}catch(HttpClientErrorException e){
logger.error(e.getResponseBodyAsString());
logger.error(e.getMessage());
return null;
}
}