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Strategy Pattern
A Strategy Pattern says that “defines a family of functionality, encapsulate each one, and make them interchangeable”.
The Strategy Pattern is also known as Policy.
Benefits:
- It provides a substitute to subclassing.
- It defines each behavior within its own class, eliminating the need for conditional statements.
- It makes it easier to extend and incorporate new behavior without changing the application.
Usage:
- When the multiple classes differ only in their behaviors.e.g. Servlet API.
- It is used when you need different variations of an algorithm.
Strategy Pattern in (Core Java API’s) or JSE 7 API’s:
Strategy Pattern in (Advance Java API’s) or JEE 7 API’s:
UML for Strategy Pattern:
Implementation of Strategy Pattern:
Step 1:
Create a Strategy interface.
Step 2:
Create a Addition class that will implement Startegy interface.
Step 3:
Create a Subtraction class that will implement Startegy interface.
Step 4:
Create a Multiplication class that will implement Startegy interface.
Step 5:
Create a Context class that will ask from Startegy interface to execute the type of strategy.
Step 6:
Create a StartegyPatternDemo class.
Output:
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