flyweightfactory.java

Java设计模式(GOF)代码样例以及文档说明

/*
 * 项目名称 Pattern
 * 包名称   com.niufish.pattern.flyweight
 * 
 * 文件名称 FlyweightFactory.java
 * 
 */
package com.niufish.pattern.flyweight;

import java.util.HashMap;

/**
 * 享元工厂角色，负责创建和管理享元角色。
 * <p>
 * <a href="FlyweightFactory.java.html"><i>View Source</i></a>
 * </p>
 * @author  Kingfish
 * @version 1.0
 */
public class FlyweightFactory {
    
    /**
     * 持有的享元对象
     */
    private HashMap _flies = new HashMap();
    
    /**
     * 得到享元对象，如果原先初始化就直接从_flies里面得到
     * @param createWhichClass 需要建立的对象的类名
     * @return 享元对象
     * @throws ClassNotFoundException 类没找到异常
     * @throws IllegalAccessException 访问异常
     * @throws InstantiationException  初始化异常
     */
    public Flyweight getFlyweight(String createWhichClass) throws InstantiationException, IllegalAccessException, ClassNotFoundException{
        if (_flies.containsKey(createWhichClass)){
            return (Flyweight)_flies.get(createWhichClass);
        }else{
            Flyweight fly = null;
            fly = (Flyweight)Class.forName(createWhichClass).newInstance();
            _flies.put(createWhichClass,fly);
            return fly;
        }
    }
    

}