单例模式

Posted 2022-12-22 shanbaoxin

public class Singleton 
    //单例设计模式，禁止指令重排可以加volatile
    private static Singleton singleton = null;

    private void Singleton() 
        System.out.println(Thread.currentThread().getName() + "构造方法执行");
    
    //DCL（Double Check lock双端检索机制）
    public static Singleton getInstance() 
        if (singleton == null) 
            synchronized (Singleton.class) 
                if (singleton == null) 
                    singleton=new Singleton();
                
            
        
        return singleton;