Adapting to Data Format Changes

Adapter Design Pattern Overview

• The Adapter pattern allows objects with incompatible interfaces to collaborate
• Used when you want to use an existing class but the interface is not compatible
• Enables cooperation with unrelated or unseen classes without subclassing each one

Problem

• Need to adapt an existing class to fit a new data structure or interface
• Modifying method signatures to fit the new data structure would require updating all dependent classes, which is impractical
• Starting over would mean discarding months of work, which is unacceptable

Adapter Structure

• The class that currently holds the necessary functionality is termed the Adaptee
• A new class, called the Adapter, is introduced to adapt the Adaptee to the new interface
• The Adapter maintains a reference to the Adaptee
• The Adapter implements a method that meets the client's new specifications, transforming the incoming data to align with the Adaptee's requirements

Example

• You have a class that sorts an ArrayList of integers, but the client wants to sort an array of integers instead
• The Adapter pattern allows you to adapt the existing class to fit the new data structure without rewriting core functionalities