设计模式之单例模式
//懒汉模式
public class Singleton { private static Singleton instance; /** * 私有化构造方法 */ private Singleton(){ } public static Singleton getInstance(){ if (instance == null){ instance = new Singleton(); } return instance; } public static void main(String[] args) { Singleton s1 = Singleton.getInstance(); Singleton s2 = Singleton.getInstance(); System.out.println(s1==s2); } }
//饿汉模式 public class Singleton { private static Singleton instance = new Singleton(); /** * 私有化构造方法 */ private Singleton(){ } public static Singleton getInstance(){ return instance; } public static void main(String[] args) { Singleton s1 = Singleton.getInstance(); Singleton s2 = Singleton.getInstance(); System.out.println(s1==s2); } }