public static void main(String[] args) {

String list2="{'result':true,'orders':[{'fee':-0.00002294,'amount':6,'price':6814.71,'contract_name':'BTC0629','create_date':1523345913000,'symbol':'btc_usd','status':2,'deal_amount':6,'lever_rate':20,'price_avg':6624.94,'order_id':564259297246208,'type':4,'unit_amount':100}]}";

JSONObject jb = JSON.parseObject(list2);

JSONArray ja = jb.getJSONArray("orders");

System.out.println(((JSONObject)ja.get(0)).get("fee"));

}