ObjectMapper ObjectNode 轉Map

        ObjectMapper objectMapper = new ObjectMapper();
        ObjectNode rootNode = objectMapper.createObjectNode();
        rootNode.put("mchid", MCH_ID)//商戶號
                .put("appid", MINI_APPID_B)//小程序appid
                .put("description", "充值")//商品描述
                .put("notify_url", NOTIFY_URL)//通知地址(回調地址)
                .put("out_trade_no", outTradeNo);//商戶內部訂單號
        rootNode.putObject("amount")//訂單金額對象
                .put("total", totalFee);//總金額  
        rootNode.putObject("payer")//支付者信息
                .put("openid", openid);

        //轉Map
        Map<String, Object> result = objectMapper.convertValue(rootNode, new TypeReference<Map<String, Object>>(){});