threadsafe singleton pattern in java
package com.journaldev.designpatterns;
public class ASingleton {
private static volatile ASingleton instance;
private static Object mutex = new Object();
private ASingleton() {
}
public static ASingleton getInstance() {
ASingleton result = instance;
if (result == null) {
synchronized (mutex) {
result = instance;
if (result == null)
instance = result = new ASingleton();
}
}
return result;
}
}