String postBody = String.format(
        "{\"offerId\":\"%s\",\"buyQuantity\":%d,\"env\":%d,\"currencyType\":\"%s\",\"productId\":\"%s\",\"goodsPrice\":%d,\"outTradeNo\":\"%s\",\"attach\":\"%s\"}",
        properties.getOfferId(),
        buyQuantity,
        properties.getEnvValue(),
        "CNY",
        productId,
        total_fee,
        outTradeNo,
        accountId.toString()
);