Implementation examplesįactory Method pattern itself can take multiple forms. Here, I’d like to focus on Factory Method and leave Abstract Factory for the future one.

Static Factory Method (already described here).

Factories often have injected dependencies that allow them to create complex objects with just minimum input data from the client. In the case of Builder, it would rather be telling: “give me instance with this and that set and leave everything else default”.

Example: Locale.forLanguageTag('pl-PL') will give us Locale instance with full country or language name even if they were not provided. When using Factory you rather tell it: “I know just this and that give me instance implementing the expected interface”. The complete interface from implementation isolation allows effortless replacing implementation in runtime. It’s Factory’s job to fulfill all required by the object dependencies.įactory can deliver objects of various types implementing the same interface just by the passed arguments. What makes it different from Builder is that usually none or very few arguments need to be passed. Instead of calling object constructor, we can call a method of the Factory which will generate interface implementation - the concrete object.

It describes an interface used to deliver instances. Just like Builder, the Factory is a creational pattern. More interesting example from the gang of four.Example from “the gang of four” (simple).

Data class kotlin serializable