Post Form Urlencoded HttpEntity

private HttpEntity<String> generateRequestEntity(Map<String, String> params) {        StringBuilder sb = new StringBuilder();        params.forEach((key, value) -> sb.append(key).append("=").append(value).append("&"));        HttpHeaders headers = new HttpHeaders();        headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));        headers.add("Content-Type", "application/x-www-form-urlencoded");        AtomicReference<HttpEntity<String>> entity = new AtomicReference<>(new HttpEntity<>(sb.toString().substring(0,sb.toString().length - 1), headers));        return entity.get();    }