【设计模式】——享元模式（23）

不念不忘少年蓝@ 2023-06-24 09:28 2阅读 0赞

一、定义

享元模式就是运用共享技术有效的支持大量细粒度的对象。

二、框架运用

String中的享元模式

三、实战

1、实现类

public abstract class WebSite {
        protected String name;
    
        public WebSite(String name) {
            this.name = name;
        }
    
        public abstract void show(User user);
    }
    
    
    public class ConcreteWebSite extends WebSite {
        public ConcreteWebSite(String name) {
            super(name);
        }
    
        @Override
        public void show(User user) {
            System.out.println("网站名称："+name+"|网站账号："+user.getAccount()+"|网站密码："+user.getPassword());
        }

2、实体类

@Data
    public class User {
        private String account;
        private String password;
    
        public User(String account, String password) {
            this.account = account;
            this.password = password;
        }
    }

3、工厂类

public class WebSiteFactory {
        private Map<String,WebSite> webSiteMap = new HashMap<>();
    
        public WebSite getWebSite(String key){
            if (!webSiteMap.containsKey(key)){
                webSiteMap.put(key,new ConcreteWebSite(key));
            }
            return webSiteMap.get(key);
        }
    
        public int getWebSiteCount(){
            return webSiteMap.size();
        }
    }

4、运行和结果

public class Client {
        public static void main(String[] args) {
            WebSiteFactory factory = new WebSiteFactory();
    
            WebSite webSiteA = factory.getWebSite("A");
            WebSite webSiteB = factory.getWebSite("B");
    
            User userA = new User("范闲","123456");
            User userB = new User("王启年","654321");
            webSiteA.show(userA);
            webSiteB.show(userB);
            System.out.println(factory.getWebSiteCount());
        }
    }
    
    
    
    Connected to the target VM, address: '127.0.0.1:56232', transport: 'socket'
    网站名称：A|网站账号：范闲|网站密码：123456
    网站名称：B|网站账号：王启年|网站密码：654321
    2
    Disconnected from the target VM, address: '127.0.0.1:56232', transport: 'socket'