@WebMethod(operationName = "ReadStock")
    public ArrayList<Stock> ReadStock(@WebParam(name = "stock_id") String stock_id) {
            Stock stock  = new Stock();
            ArrayList<Stock> stocks = new ArrayList<Stock>();
            ArrayList<QueryCriteria> qc = new ArrayList<QueryCriteria>();
            if(!stock_id.equals("-1")){
                qc.add(new QueryCriteria("stock_id", stock_id, Operand.EQUALS));
            }
            ArrayList<String> fields = new ArrayList<String>();
            ArrayList<QueryOrder> order = new ArrayList<QueryOrder>();
        try {
           stocks = stock.Read(qc, fields, order);
        } catch (SQLException ex) {
            Logger.getLogger(JAX_WS.class.getName()).log(Level.SEVERE, null, ex);
        }
            if(stocks.isEmpty()){
                return null;
            }
        return stocks;
    }