Generic Singleton Implementation

Here's a helpful class that I've been using for implementing singleton objects through the years. This way I can use any class (as long as it has a default constructor) as a singleton object. Originally, I called this class the YetAnotherSingleton< T > but that was simply too unprofessional and I ended up renaming it.

public static class Singleton<T> where T : class, new()

{

    private static readonly object staticLock = new object();

    private static T instance;

    public static T GetInstance()

    {

        lock (staticLock)

        {

            if (instance == null)

                instance = new T();

            return instance;

        }

    }

    public static void Dispose()

    {

        if (instance == null)

            return;

        var disposable = instance as IDisposable;

        if (disposable != null)

            disposable.Dispose();

        instance = null;

    }

}

And here's an example of how to use the class above. To improve performance of web service calls its a good idea to use a singleton instance of the web service proxy class.

public static class ServiceClientFactory

{

    public static Service GetService()

    {

        var ws = Singleton<Service>.GetInstance();

        ws.Url = ConfigurationManager.AppSettings["ServiceUrl"];

        ws.Credentials = GetCredentials();

        return ws;

    }

    private static ICredentials GetCredentials()

    {

        var username = ConfigurationManager.AppSettings["ServiceUsername"];

        var password = ConfigurationManager.AppSettings["ServicePassword"];

        var domain = ConfigurationManager.AppSettings["ServiceDomain"];

        return new NetworkCredential(username, password, domain);

    }

}

In my next few articles I'll be sharing code from my design pattern framework that I've been using through the years.