What is the difference between Factory and Strategy patterns?

java design-patterns factory-pattern strategy-pattern abstract-factory
Sappidireddy picture Sappidireddy · Mar 5, 2009 · Viewed 56.2k times · Source

Can any one explain the difference between factory and strategy patterns?

For me both are looking same other than an extra factory class (which create an object of product in factory patterns)

Answer

tvanfosson picture tvanfosson · Mar 5, 2009

A factory pattern is a creational pattern. A strategy pattern is an operational pattern. Put another way, a factory pattern is used to create objects of a specific type. A strategy pattern is use to perform an operation (or set of operations) in a particular manner. In the classic example, a factory might create different types of Animals: Dog, Cat, Tiger, while a strategy pattern would perform particular actions, for example, Move; using Run, Walk, or Lope strategies.

In fact the two can be used together. For example, you may have a factory that creates your business objects. It may use different strategies based on the persistence medium. If your data is stored locally in XML it would use one strategy. If the data were remote in a different database, it would use another.

Related questions

How to avoid 'instanceof' when implementing factory design pattern?

I am attempting to implement my first Factory Design Pattern, and I'm not sure how to avoid using instanceof when adding the factory-made objects to lists. This is what I'm trying to do: for (ABluePrint bp : bluePrints) { AVehicle v = AVehicleFactory.…

Read More
Factory design pattern - Not use static methods because unit testing is a problem

I know this question has been asked several times in stackoverflow but somehow still had some trouble figuring out a solution. The following example I think is a good case to have static methods public class ConnectionFactory { public static Connection …

Read More
Examples of GoF Design Patterns in Java's core libraries

I am learning GoF Java Design Patterns and I want to see some real life examples of them. What are some good examples of these Design Patterns in Java's core libraries?

Read More