最优单例-枚举单例

最优单例-枚举单例

package cn.kingdom.web.controller.navigation;

import cn.kingdom.common.bean.Site;

/**
 * 枚举类型单例
 *
 * @author zhang
 * @date 2019-03-07:32:27
 */
public class Test {

    public static Site getInstance() {
        return Singleton.INSTANCE.getInstance();
    }

    private enum Singleton {
        /** 实例 */
        INSTANCE;

        private Site singletonSite;

        Singleton() {
            System.out.println("初始化枚举类");
            singletonSite = new Site();
        }

        public Site getInstance() {
            System.out.println("调用枚举内部方法");
            return singletonSite;
        }
    }

    public static void main(String[] args) {
        Site instance = getInstance();
        Site instance2 = getInstance();
        Site instance3 = getInstance();

    }

}