Introduction:
The Strategy Pattern is a behavioral design pattern that allows defining a family of algorithms, encapsulating each one, and making them interchangeable. In this tutorial, we’ll explore the Strategy Pattern using a duck behavior example in Java.
Understanding the Strategy Pattern
The Strategy Pattern consists of three main components:
- Strategy: This is an interface defining a set of algorithms. The strategies are interchangeable and encapsulate the algorithms’ behavior.
- Concrete Strategies: These are the implementations of the Strategy interface, each representing a specific algorithm.
- Context: This is a class that uses the Strategy interface to perform the desired behavior. The context allows switching between different strategies dynamically.
Example: Duck Behavior
Consider a scenario where we have different types of ducks with different behaviors, such as flying and quacking. We want to model this behavior using the Strategy Pattern.
Step 1: Define the Strategy Interface
First, we define the FlyBehavior and QuackBehavior interfaces representing the flying and quacking behaviors, respectively.
Step 2: Implement Concrete Strategies
Next, we implement concrete strategies for flying and quacking behaviors.
Step 3: Create a Context Class
Now, we create a Duck class which acts as the context and utilizes the flying and quacking behaviors.
Step 4: Implement Concrete Duck Types
Finally, we create concrete duck types that extend the Duck class and specify their display.
Step 5: Use the Duck Objects
Now, we can create duck objects and observe their behaviors.
Output
I'm a Mallard duck
Flying with wings
Quack
I'm a Rubber duck
Unable to fly
SqueakConclusion
The Strategy Pattern provides a flexible way to define a family of algorithms, encapsulate each one, and make them interchangeable. In this tutorial, we used the Strategy Pattern to model different behaviors of ducks in a Java application. This pattern allows us to add new behaviors easily and facilitates code reuse.
