flyweightfactorysingleton.java

这个文件里面包含了java设计模式的一些例子讲解

package com.javapatterns.flyweight.composite;

import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;

public class FlyweightFactorySingleton
{
    /**
     * @label Creates 
     */
    private static FlyweightFactorySingleton myself =
        new FlyweightFactorySingleton();

    private HashMap flies = new HashMap();
    /**
     * @link aggregation
     * @directed
     * @clientRole Flyweights
     */
    private Flyweight lnkFlyweight;

	private FlyweightFactorySingleton(){}

    public static FlyweightFactorySingleton getInstance()
    {
		return new FlyweightFactorySingleton();
    }

	public synchronized Flyweight factory(String complexState)
	{ 
		ConcreteCompositeFlyweight complexFly = new ConcreteCompositeFlyweight();
		
		int length = complexState.length();
        Character state = null;

		for(int i = 0; i < length; i++)
		{ 
			state = new Character(complexState.charAt(i) );
            System.out.println("factory(" + state + ")");
			complexFly.add( state, this.factory(state) );
		}
		return complexFly;
    }

	public Flyweight factory(Character state)
	{ 
		if ( flies.containsKey( state ) )
        {
            return (Flyweight) flies.get( state );
        }
        else
        {
			Flyweight fly = new ConcreteFlyweight( state );
            flies.put( state , fly);
            return fly;
        }
	}
	
	public void checkFlyweight()
	{ 
		Flyweight fly ;
        int i = 0 ;

        System.out.println("\n==========checkFlyweight()=============");
		for ( Iterator it = flies.entrySet().iterator() ; it.hasNext() ;  )
        {
			Map.Entry e = (Map.Entry) it.next();
            System.out.println( "Item " + (++i) + " : " + e.getKey());
        }
        System.out.println("\n==========checkFlyweight()=============");
	}

}