（可选）扩展消费端

此可选部分演示如何针对更为复杂的场景扩展消费端代码。

如果要了解每分钟的最大销售订单数，可以修改三个位置的 StockStats 类以适应此新的优先级。

扩展消费端

1. 添加新实例变量：

   
    // Ticker symbol of the stock that had the largest quantity of shares sold 
    private String largestSellOrderStock;
    // Quantity of shares for the largest sell order trade
    private long largestSellOrderQuantity;
                   

2. 将以下代码添加到 addStockTrade：

   
   if (type == TradeType.SELL) {
        if (largestSellOrderStock == null || trade.getQuantity() > largestSellOrderQuantity) {
            largestSellOrderStock = trade.getTickerSymbol();
            largestSellOrderQuantity = trade.getQuantity();
        }
    }
                   

3. 修改 toString 方法以打印其他信息：

    
   public String toString() {
       return String.format(
           "Most popular stock being bought: %s, %d buys.%n" +
           "Most popular stock being sold: %s, %d sells.%n" +
           "Largest sell order: %d shares of %s.",
           getMostPopularStock(TradeType.BUY), getMostPopularStockCount(TradeType.BUY),
           getMostPopularStock(TradeType.SELL), getMostPopularStockCount(TradeType.SELL),
           largestSellOrderQuantity, largestSellOrderStock);
   }
                   

如果您现在运行消费端（请记住同时运行创建器），则应看到类似于以下内容的输出：

 
  ****** Shard shardId-000000000001 stats for last 1 minute ******
  Most popular stock being bought: WMT, 27 buys.
  Most popular stock being sold: PTR, 14 sells.
  Largest sell order: 996 shares of BUD.
  ****************************************************************
        

后续步骤

清理资源