Factory Method Example
This program demonstrates Factory Method design pattern.
Problem Statement
Write a Java program to implement Factory Method for creating documents.
Source Code
| 1 | abstract class Document { |
| 2 | abstract void open(); |
| 3 | } |
| 4 | class PDF extends Document { |
| 5 | void open(){ System.out.println("Opening PDF"); } |
| 6 | } |
| 7 | class Word extends Document { |
| 8 | void open(){ System.out.println("Opening Word"); } |
| 9 | } |
| 10 | abstract class DocumentFactory { |
| 11 | abstract Document createDocument(); |
| 12 | } |
| 13 | class PDFDocumentFactory extends DocumentFactory { |
| 14 | Document createDocument(){ return new PDF(); } |
| 15 | } |
| 16 | class WordDocumentFactory extends DocumentFactory { |
| 17 | Document createDocument(){ return new Word(); } |
| 18 | } |
| 19 | public class FactoryMethod { |
| 20 | public static void main(String[] args) { |
| 21 | System.out.println("Eduinq Factory Method"); |
| 22 | DocumentFactory df=new PDFDocumentFactory(); |
| 23 | Document d=df.createDocument(); |
| 24 | d.open(); |
| 25 | } |
| 26 | } |
Program Output
Eduinq Factory Method Opening PDF
Explanation
Factory Method delegates creation to subclasses. - Each factory creates specific product. - This promotes extensibility and adherence to OCP (Open Closed Principle). Conclusion: Shows how to implement Factory Method pattern.