Java 单例模式基础
1. 概念: 确保某个类只有一个实例
2. 实现理论:
(1) 将构造方法限定为private避免了类在外部被实例化;
(2)提供唯一访问(获取)实例的方法;
1 public class Singleton { 2 private static Singleton uniqueInstance = null; 3 private Singleton() {} 4 public static Singleton getInstance() { 5 if (uniqueInstance == null) { 6 uniqueInstance = new Singleton(); 7 } 8 return uniqueInstance; 9 } 10 }