Java单例模式简单实现

代码

public class Singleton {
    private static Singleton singleton;//创建一个单例对象

    public static Singleton getSingleton(){
        if(singleton == null){//判断对象是否为空
            singleton = new Singleton();
        }
        return singleton;
    }
}

public class Test {
    public static void main(String[] args) {
        Singleton s1 = Singleton.getSingleton();
        Singleton s2 = Singleton.getSingleton();

        System.out.println(s1 == s2);            //输出true
        System.out.println(s1.equals(s2));        //输出true
    }
}