ObjectMapper ObjectNode 转Map

        ObjectMapper objectMapper = new ObjectMapper();
        ObjectNode rootNode = objectMapper.createObjectNode();
        rootNode.put("mchid", MCH_ID)//商户号
                .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(回调地址)
                .put("out_trade_no", outTradeNo);//商户内部订单号
        rootNode.putObject("amount")//订单金额对象
                .put("total", totalFee);//总金额  
        rootNode.putObject("payer")//支付者信息
                .put("openid", openid);

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