【Java多线程】之八：单例模式的线程安全

Singleton is one of the most widely used creational design pattern to restrict the object creation by applications. In real world applications, resources like Database connections or Enterprise Information Systems (EIS) are limited and should be used wisely to avoid any resource crunch. To achieve this, we can implement Singleton design pattern to create a wrapper class around the resource and limit the number of object created at runtime to one.

ASingleton.java

package com.journaldev.designpatterns;

public class ASingleton{

private static ASingleton instance= null;
private static Object mutex= new Object();
private ASingleton(){
}

public static ASingleton getInstance(){
if(instance==null){
synchronized (mutex){
if(instance==null) instance= new ASingleton();
}
}
return instance;
}
}

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