设计模式（享元模式）-白红宇

设计模式（享元模式）

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发布时间：2019-06-27

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享元模式可以理解是一个对象的缓存，通过构建一个享元工厂对所有的对象进行管理。

代码如下：

Flyweight 享元的接口

public interface Flyweight {    public void doAction();}

FlyweightImpl 具体被共享的类实现

public class FlyweightImpl implements Flyweight{    @Override    public void doAction() {        System.out.println("doAction");    }}

FlyweightFactory 享元工厂

public class FlyweightFactory {    private static Map
     
       flyweights         = new HashMap
      
       ();    public static Flyweight getFlyweight(String key) {        if (flyweights.get(key) == null) {            flyweights.put(key, new FlyweightImpl());        }        return (Flyweight) flyweights.get(key);    }    public static int getSize() {        return flyweights.size();    }}

APP 测试类

public class App {    public static void main(String[] args) {        FlyweightFactory factory = new FlyweightFactory();        factory.getFlyweight("a").doAction();        factory.getFlyweight("b").doAction();        factory.getFlyweight("a").doAction();                System.out.println(factory.getSize());    }}