Java设计模式之享元模式示例详解

public class User {
    private String name;

    public User(String name){
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

public abstract class Website {
    public abstract void show(User user);
}

public class ConcreteWebsite extends Website{
    // 网站的发布形式
    private String type;

    public ConcreteWebsite(String type){
        this.type = type;
    }

    @Override
    public void show(User user) {
        System.out.println("以" + type + "形式发布网站");
        System.out.println("网站的用户名是：" + user.getName());
    }
}

public class WebsiteFactory {
    // 创建HashMap,充当池的角色
    private HashMap<String, ConcreteWebsite> pool = new HashMap<String, ConcreteWebsite>();

    // 根据类型判断，获取池子里的对象
    public Website getWebsite(String type){
        if(!pool.containsKey(type)){
            pool.put(type,new ConcreteWebsite(type));
        }
        return pool.get(type);
    }

    // 获取池子里的对象总数
    public int getWebsiteCount(){
        System.out.println("当前池子里的对象总数：" + pool.size());
        return pool.size();
    }
}

public class Client {
    public static void main(String[] args) {
        //创建一个享元工厂
        WebsiteFactory websiteFactory = new WebsiteFactory();
        Website news = websiteFactory.getWebsite("新闻");
        news.show(new User("老李"));
        Website wechat = websiteFactory.getWebsite("博客");
        wechat.show(new User("老高"));
        websiteFactory.getWebsiteCount();
        Website wechat1 = websiteFactory.getWebsite("微信");
        wechat.show(new User("老沈"));
        websiteFactory.getWebsiteCount();
    }
}