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How does a singleton work with creation parameters?
A Singleton with parameters smells fishy to me. Obviously, x==y and y works with x’s creation parameters, while y’s creation parameters are simply ignored. Results are probably… confusing at least.
How are singletons used in a C # class?
Essentially, a singleton is a class which only allows a single instance of itself to be created, and usually gives simple access to that instance. Most commonly, singletons don’t allow any parameters to be specified when creating the instance – as otherwise a second request for an instance but with a different parameter could be problematic!
When to use factory pattern or singleton pattern?
Most commonly, singletons don’t allow any parameters to be specified when creating the instance – as otherwise a second request for an instance but with a different parameter could be problematic! (If the same instance should be accessed for all requests with the same parameter, the factory pattern is more appropriate.)
When to use Singleton in a multithreading environment?
In a multithreading environment, add synchronisation to avoid race conditions. Singleton is ugly but since user whateva can’t be bothered to correct his own code… Skeet blogged about this years ago I think, it’s pretty reliable.
How to create singleton class with static HashMap?
If the parameters feeding the Singleton class are got dynamically during the running of your program, simply use a static HashMap storing different instances in your Singleton class to ensure that for each parameter (s), only one instance is created.
Is it a violation of singleton pattern in Java?
By having a constructor with parameter, you can build flexibility into your code to change some attributes of your singleton object every time you run you application. This is not a violation of Singleton pattern. It looks like a violation if you see this from code perspective.
What’s the point of a singleton in Java?
A singleton, by definition, is an object you want to be instantiated no more than once. If you are trying to feed parameters to the constructor, what is the point of the singleton? You have two options. If you want your singleton to be initialized with some data, you may load it with data after instantiation, like so: