DoubleCheckSingleton.java

package com.cs.volatileT;

public class DoubleCheckSingleton {
    private static volatile DoubleCheckSingleton _instance = null;

    public static DoubleCheckSingleton getInstance() {
        if (_instance == null) {
            synchronized (DoubleCheckSingleton.class) {
                if (_instance == null) {
                    _instance = new DoubleCheckSingleton();
                }
            }
        }

        return _instance;
    }
}