Java发起post请求并以FormData携带数据

List body = new ArrayList<>();
body.add(new BasicNamevaluePair(key, value));
String bodyString = URLEncodedUtils.format(body, "utf-8");
Map headers = new HashMap<>();
headers.put("Content-Type", "application/x-www-form-urlencoded");
String accessJson = HttpClientHelper.post(ACCESS_URL, headers, bodyString);