How to Redirect request as post using ResponseEntity - spring

Question

I trying to include response from other url from ResponseEntity for oauth authorization but it is failing as I am unable to specify request method.
Below is the code
#RequestMapping(value = "/login/otp", method = RequestMethod.POST, produces = {MediaType.APPLICATION_JSON_UTF8_VALUE})
#ResponseBody
public ResponseEntity<?> getOTP(#Valid #RequestBody String loginDtls,UriComponentsBuilder ucBuilder) {
LoginDAO login = null;
ResponseEntity<?> resp = null;
try {
ObjectMapper mapper = new ObjectMapper();
String userId = "";
try {
JsonNode root = mapper.readTree(loginDtls);
userId = root.get("userId").textValue();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("UserController : getting otp for contact "+ userId);
login = loginService.findByUserId(userId);
if (login==null) {
System.out.println("A UserDAO with name " + userId + " does not exist");
resp = new ResponseEntity<String>(HttpStatus.NOT_FOUND);
}
String otp = GenUtil.generateOTP();
LoginDAO loginUpd = new LoginDAO(login);
loginUpd.setOtp(otp);
loginUpd.setOtpTimestamp(new Timestamp(System.currentTimeMillis()));
loginService.updateLogin(loginUpd);
System.out.println(loginUpd);
resp = getAuthenticated(ucBuilder);
System.out.println(resp.getStatusCodeValue());
System.out.println(resp.getBody());
}catch(Exception e) {
e.printStackTrace();
}
resp = new ResponseEntity<String>(login.toString(), HttpStatus.OK);
return resp;
}
private ResponseEntity<?> getAuthenticated(UriComponentsBuilder ucBuilder){
HttpHeaders headers = new HttpHeaders();
URI uri= ucBuilder.path("/oauth/token"+PASSWORD_GRANT).build().toUri();
List<MediaType> accept = new ArrayList<MediaType>();
accept.add(MediaType.APPLICATION_JSON_UTF8);
headers.setAccept(accept);
headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
headers.setBasicAuth("my-trusted-client", "secret");
System.out.println(headers);
ResponseEntity<?> resp = ResponseEntity.created(uri).headers(headers).build();
return resp;
}