promotionadvisor.java

本书透彻讲解了经典的《设计模式：可复用面向对象软件的基础》一书涵盖的23种基本设计模式。本书将这些设计模式分成五类：接口型模式、责任型模式、构造型模式、操作型模式

package com.oozinoz.recommend;

import java.util.Properties;

import com.oozinoz.fireworks.Firework;

/*
 * Copyright (c) 2001 Steven J. Metsker.
 * 
 * Steve Metsker makes no representations or warranties about
 * the fitness of this software for any particular purpose, 
 * including the implied warranty of merchantability.
 *
 * Please use this software as you wish with the sole
 * restriction that you may not claim that you wrote it.
 */
/**
 * Implement the Advisor interface, recommending a currently
 * promoted firework.
 * 
 * @author Steven J. Metsker
 */
public class PromotionAdvisor implements Advisor 
{
	public static final PromotionAdvisor singleton =
		new PromotionAdvisor();
	private Firework promoted;
// look for a promoted firework
private PromotionAdvisor()
{
	try
	{
		Properties p = new Properties();
		p.load(
			ClassLoader.getSystemResourceAsStream(
				"config/strategy.dat"));
		String promotedFireworkName = p.getProperty("promote");
		if (promotedFireworkName != null)
		{
			promoted = Firework.lookup(promotedFireworkName);
		}
	}
	catch (Exception e)
	{
	}
}
/**
 * Return true if the constructor was able to find a
 * promoted firework.
 *
 * @return true if the constructor was able to find a
 *         promoted firework.
 */
public boolean hasItem()
{
	return promoted != null;
}
/**
 * Recommend a nice item for this customer, based what we're
 * promoting.
 *
 * @param Customer the customer to cross-sell
 * @return a nice item for the customer to buy
 */
public Firework recommend(Customer c)
{
	return promoted;
}
}