Double Locking Or Double check in Singleton Class

Double Locking Or Double Check in Singleton

Now these days it is a frequently asked question that how you will create double locking singleton class.

It is nothing new as earlier we were using Synchronize key-work before method, the same key world we will use while creating instance of the singleton class.

See the below written code snap.


private SingletonInstance instance=null;

 public SingletonInstance getInstance() {

        if (instance == null) {

            synchronized (SingletonInstance.class) {

                if (instance == null) {

                    instance = new SingletonInstance();

                }

            }

        }

        return instance;

    }