最近在做一个聊天室,在设计类的时候遇到一个问题:不知道如何保证每一个用户对象(不同的USER类实例)进入同一个聊天室对象(唯一的Room类实例),也就是说,所有用户登陆后只进入一个聊天室,这个聊天室对象是全局唯一的。研究了一下才知道这原来就是设计模式中的singleton模式。
以下是Room类的关键代码:
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public class Room
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{
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private static Room room;//声明一个静态的Room类变量
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private Room()//构造函数私有,防止实例化
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{
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//
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//TODO: 在此处添加构造函数逻辑
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//
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}
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public static Room GetRoom()//获取实例的方法,供外部调用
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{
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if (room == null)//若实例不存在,创建实例,否则返回已有的实例;
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{
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room = new Room();
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}
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return room;
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}
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}
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客户端调用代码:
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