享元模式（咖啡屋）【java与模式】

package com.javapatterns.flyweight.coffeeshop;

public class Flavor extends Order
{  
    private String flavor;
    
    public Flavor(String flavor)
    {
        this.flavor = flavor;
    }
    
    public String getFlavor()
    {
        return this.flavor;
    }
    
    public void serve(Table table)
    {
        System.out.println("Serving table " + table.getNumber() + " with flavor " + flavor );
    }
}

package com.javapatterns.flyweight.coffeeshop;

public class Table
{
    private int number;

    public Table(int number)
    {
        this.number = number;
    }

    public void setNumber(int number)
    {
        this.number = number;
    }

    public int getNumber()
    {
        return number;
    }

}

package com.javapatterns.flyweight.coffeeshop;

public class FlavorFactory
{  
    /**
     * @label Flyweight
     * @link aggregation
     */
    private Order[] flavors = new Flavor[10];
    private int ordersMade = 0;
    private int totalFlavors = 0 ;
    
    public Order getOrder(String flavorToGet)
    {
        if (ordersMade > 0)
        {
            for (int i = 0; i < ordersMade; i++)
            {
                if (flavorToGet.equals((flavors[i]).getFlavor()))
                {
                    return flavors[i];
                }
            }
        }
        flavors[ordersMade] = new Flavor(flavorToGet);
        totalFlavors++;
        return flavors[ordersMade++];
    }
    
    public int getTotalFlavorsMade()
    {
         return totalFlavors;
    }
}

package com.javapatterns.flyweight.coffeeshop;

public class Client
{
    //the flavors ordered


    /**
     * @label Creates 
     */
    private static Order[] flavors = new Flavor[100];

    private static int ordersMade = 0;
    private static FlavorFactory flavorFactory;

    /** @link dependency */
    /*#Table lnkTable;*/
     
    private static void takeOrders(String aFlavor)
    {
        flavors[ordersMade++] = flavorFactory.getOrder(aFlavor);
    }
     
    public static void main(String[] args) 
    {
        flavorFactory = new FlavorFactory();
        
        takeOrders("Black Coffee");
        takeOrders("Capucino");
        takeOrders("Espresso");
        takeOrders("Espresso");
        takeOrders("Capucino");
        takeOrders("Capucino");
        takeOrders("Black Coffee");
        takeOrders("Espresso");
        takeOrders("Capucino");
        takeOrders("Black Coffee");
        takeOrders("Espresso");

        for (int i = 0; i < ordersMade; i++)
        {
            flavors[i].serve(new Table(i));
        }

        System.out.println("
Total teaFlavor objects made: " +
            flavorFactory.getTotalFlavorsMade());
    }
}

《java与模式》中的咖啡屋代码，拿来理解“享元模式”非常合适！