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Should factory be a singleton?
Factory pattern delegates the responsibility of creating the instances (objects) to the factory classes. But, singleton pattern ensures the creation of an object should be done only once per application instance.
What if I use static instead making Singleton?
While a static class is generally initialized when it is first loaded and it will lead to potential class loader issues. Singleton Objects stored on heap while static class stored in stack. Singleton Objects can have constructor while Static Class cannot.
Are static objects Singleton?
Main differences are: Singleton has an instance/object while static class is a bunch of static methods. Singleton can be extended e.g. through an interface while static class can’t be.
Should a factory be static?
No, factory class by default shouldn’t be static. Actually, static classes are not welcomed in OOP world since they can also convey some state and therefore introduce global application state. If you need only one factory object to be present, you can control it’s creation through singleton pattern.
Can you inherit from a singleton?
Unlike static classes, Singleton classes can be inherited, can have base class, can be serialized and can implement interfaces. You can implement Dispose method in your Singleton class.
What’s the difference between a singleton class and a static class?
A static class is one that has only static methods, for which a better word would be “functions”. The design style embodied in a static class is purely procedural. Singleton, on the other hand, is a pattern specific to OO design.
How is a singleton used in a factory pattern?
Singleton returns the same instance of class all the time, factory can create objects by instantiating various classes, or by using other allocation schemes such as an object pool. so singleton can be used in factory pattern
Which is an example of a singleton class in Java?
JDK has examples of both singleton and static, on the one hand java.lang.Math is a final class with static methods, on the other hand java.lang.Runtime is a singleton class.
Which is the best definition of a factory method?
A Factory method is a method that encapsulates the creation or instantiation of a type so that the type itself has control over how it is instantiarted.