code: private static void callbackResult(String str, String pubKey, ICheckLoginSignHandler callback){
          JSONObject json = null;
          try {
              json = new JSONObject(str);
          } catch (JSONException e) {
              callback.onCheckResult(null, "json parse fail:" + e.getMessage(), false);
              return;
          }
  
          String rtnCode = json.optString("rtnCode");
          String errMsg = json.optString("errMsg");
          String ts = json.optString("ts");
          String rtnSign = json.optString("rtnSign");
  
          if("0".equals(rtnCode))
          {
              String nosign = "rtnCode=" + RSAUtil.urlEncode(rtnCode) + "&ts=" + RSAUtil.urlEncode(ts);
              boolean s = RSAUtil.doCheck(nosign, rtnSign, pubKey);
              callback.onCheckResult(rtnCode, "request success", s);
          } else {
              callback.onCheckResult(rtnCode, "request sign fail:" + errMsg, false);
          }
      }
docs: 回调验签请求结果
  @param str 验签请求结果字符串
  @param pubKey 公钥
  @param callback 回调