单例模式（懒汉）

Posted 2022-01-27 wanerhu

/**
 * 单例模式（懒汉）
 */

public class Single 

    private static Single single=null;

    private Single()

    

    public static Single getInstance()
        if (single == null)
            single=new Single();
        
        return single;
    

测试是否为单例

public static void main(String[] args) 
        Single single1 = Single.getInstance();
        Single single2 = Single.getInstance();
        System.out.println(single1 == single2);