命令模式

import java.util.List;
import java.util.ArrayList;

class Stock {
    public void buy() {
        System.out.println("buy 10 stocks");
    }

    public void sell() {
        System.out.println("shell 10 stocks");
    }
}


interface Order {
    public void excuate();
}

class ByStocks implements Order {
    private Stock stock;
    public ByStocks(Stock stock) {
        this.stock = stock;
    }
    public void excuate() {
        stock.buy();
    }
}


class ShellStocks implements Order {
    private Stock stock;
    public ShellStocks(Stock stock) {
        this.stock = stock;
    }
    public void excuate() {
        stock.sell();
    }
}

class Broker {
    private static List<Order> lists = new ArrayList<Order>();

    public static void orderStore(Order order) {
        lists.add(order);
    }

    public static void orderExecute() {
        for (Order list : lists) {
            list.excuate();
        }
        lists.clear();
    }

}


public class CommandPatternDemo {
    public static void main(String args[]) {
        Stock stock = new Stock();

        Order buyStock = new ByStocks(stock);
        Order shellStock = new ShellStocks(stock);

        Broker.orderStore(buyStock);
        Broker.orderStore(shellStock);

        Broker.orderExecute();
    }
}