Question: When Should I Use Singleton?

What is the benefit of Singleton pattern?

Instance control: Singleton prevents other objects from instantiating their own copies of the Singleton object, ensuring that all objects access the single instance.

Flexibility: Since the class controls the instantiation process, the class has the flexibility to change the instantiation process..

Why can’t we use static class instead of Singleton?

Static means that it belongs to a class it is in and not to any instance. So it cannot be a top level class. – Static class will have all its member as static only unlike Singleton. – It can be lazily loaded whereas static will be initialized whenever it is first loaded.

Why is Singleton bad?

By using singletons in your project, you start to create technical debt. Singletons tend to spread like a virus because it’s so easy to access them. It’s difficult to keep track of where they’re used and getting rid of a singleton can be a refactoring nightmare in large or complex projects.

When would you use a singleton?

A singleton should be used when managing access to a resource which is shared by the entire application, and it would be destructive to potentially have multiple instances of the same class. Making sure that access to shared resources thread safe is one very good example of where this kind of pattern can be vital.

When should you not use a singleton?

The only situation in which you should consider a singleton is when having more than one instance of already global data would actually be a logical or hardware access error….Related Links:Brittleness invoked by Global State and Singletons.Dependency Injection to Avoid Singletons.Factories and Singletons.

Why is singleton class used?

In Java the Singleton pattern will ensure that there is only one instance of a class is created in the Java Virtual Machine. It is used to provide global point of access to the object. In terms of practical use Singleton patterns are used in logging, caches, thread pools, configuration settings, device driver objects.