java 单例模式

Posted 2022-04-15 zheng123

package javalearn;

public class SingleInstance 
    private volatile static SingleInstance instance;
    private SingleInstance()

    
    public static SingleInstance getInstance()
        if (instance==null)
            synchronized(SingleInstance.class)
                if (instance==null)
                    instance = new SingleInstance();
                
            
        
        return instance;