Factory Design Pattern

README.md

@@ -1,2 +1,30 @@
-# DesignPatternsJava9
-This repo consists Gang of Four Design patterns code on Java 9. Each branch in the repository has code of 1 design pattern. Switch repository to try out different design patterns.
+# What is Factory Design Pattern 
+Factory pattern creates object without exposing the creation logic to the client and refer to newly created object using a common interface.
+
+## Diagram
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/factory/diagrams/3.4%20Factory%20Design%20Pattern.png "Diagram")
+
+![Diagram](https://github.com/premaseem/DesignPatternsJava9/blob/factory/diagrams/Factory%20Icecream%20sequene%20diagram.png "Diagram")
+
+### When to use Factory Design Pattern 
+Factory design pattern is used when we have a super class with multiple sub-classes and based on input one of the sub-class is expected to be returned.
+
+### Learn Design Patterns with Java by Aseem Jain
+This repository contains working project code used in video Course by Packt Publication with title "Learn Design Patterns with Java " authored by "Aseem Jain".
+
+### Course link: 
+https://www.packtpub.com/application-development/learn-design-patterns-java-9-video
+
+### ![ http://in.linkedin.com/in/premaseem](https://github.com/premaseem/DesignPatternsJava9/blob/master/linkedin.png "http://in.linkedin.com/in/premaseem") Profile: http://in.linkedin.com/in/premaseem
+
+### Authors blog on design patterns:
+https://premaseem.wordpress.com/category/computers/design-patterns/
+
+### Software Design pattern community face book page:
+https://www.facebook.com/DesignPatternGuru/
+
+### Note: 
+* This code base will work on Java 9 and above versions. 
+* `diagrams` folders carry UML diagrams.
+* `pattern` folder has code of primary example. 
+* `patternBonus` folder has code of secondary or bonus example.

pattern/src/com/premaseem/Client.java

@@ -6,8 +6,61 @@
 @link: https://premaseem.wordpress.com/category/computers/design-patterns/
 @copyright: 2018 Packt Publication
 */
+
+import com.premaseem.icecreams.ChocolateIceCream;
+import com.premaseem.icecreams.IceCream;
+import com.premaseem.icecreams.StrawberryIceCream;
+
+import java.util.Scanner;
+
 public class Client {
  public static void main (String[] args) {
- System.out.println("Singleton cook example ");
+ System.out.println("Ice cream factory example ");
+ System.out.println("Please enter your ice cream choice");
+ System.out.println("Strawberry");
+ System.out.println("Chocolate");
+
+ Scanner scan = new Scanner(System.in);
+ String iceCreamChoice = scan.next();
+
+// Tight coupling
+// StrawberryIceCream strawberryIceCream =null;
+// ChocolateIceCream chocolateIceCream = null;
+
+ // Loose coupling using interface
+ IceCream iceCream = null;
+
+// Sphegati code with if else ladder
+// if (iceCreamChoice.equalsIgnoreCase("Strawberry")){
+// strawberryIceCream = new StrawberryIceCream();
+// }else if (iceCreamChoice.equalsIgnoreCase("Chocolate")){
+// chocolateIceCream = new ChocolateIceCream();
+// }
+
+ // Crisp, reusable, centralized code using factory
+ // IceCreamFactory iceCreamFactory = new IceCreamFactory();
+
+ // Virtual constructor ( takes care of configuration )
+ iceCream = IceCreamFactory.createIceCream(iceCreamChoice);
+
+// Repeatative code to even print
+// System.out.print("Ice cream of your choice is ");
+// if (strawberryIceCream != null){
+// System.out.println(strawberryIceCream);
+// }
+//
+// if (chocolateIceCream != null){
+// System.out.println(chocolateIceCream);
+// }
+
+ System.out.print("Ice cream of your choice is "+ iceCream.getIceCreamName());
+ System.out.println(iceCream);
+
+ System.out.println("Lessons Learnt");
+ System.out.println("Creation is easy and simplified with virtual constructor");
+ System.out.println("Centralized code easy to maintain and extend");
+ System.out.println("Loosely coupled code with interface");
+ System.out.println("Polymorphism in full force");
+
  }
 }

pattern/src/com/premaseem/IceCreamFactory.java

@@ -0,0 +1,27 @@
+package com.premaseem;
+
+import com.premaseem.icecreams.ChocolateIceCream;
+import com.premaseem.icecreams.IceCream;
+import com.premaseem.icecreams.StrawberryIceCream;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+
+public class IceCreamFactory {
+
+ static public IceCream createIceCream(String iceCreamChoice){
+ IceCream iceCream = null;
+
+ if (iceCreamChoice.equalsIgnoreCase("Strawberry")){
+ iceCream = new StrawberryIceCream(2,120);
+
+ }else if (iceCreamChoice.equalsIgnoreCase("Chocolate")){
+ iceCream = new ChocolateIceCream(2,250);
+ }
+
+ return iceCream;
+ }
+}

pattern/src/com/premaseem/icecreams/ChocolateIceCream.java

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+package com.premaseem.icecreams;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+public class ChocolateIceCream implements IceCream {
+
+ public ChocolateIceCream (Integer cost, Integer calories){
+ this.cost =cost;
+ this.calories =calories;
+ }
+
+ String brand = "";
+ Integer cost = 0;
+ Integer calories = 0;
+
+ public String toString () {
+ return this.getClass().getSimpleName() + " with Calories: " + getCalories() + " and cost: $" + getCost();
+ }
+
+ @Override
+ public Integer getCalories () {
+ return calories;
+ }
+
+ @Override
+ public Integer getCost () {
+ return cost;
+ }
+
+ @Override
+ public String getIceCreamName () {
+ return this.getClass().getSimpleName();
+ }
+}

pattern/src/com/premaseem/icecreams/IceCream.java

@@ -0,0 +1,16 @@
+package com.premaseem.icecreams;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+public interface IceCream {
+
+ Integer getCalories();
+ Integer getCost();
+ String getIceCreamName();
+
+
+
+}

pattern/src/com/premaseem/icecreams/StrawberryIceCream.java

@@ -0,0 +1,37 @@
+package com.premaseem.icecreams;
+
+/*
+@author: Aseem Jain
+@title: Design Patterns with Java 9
+@link: https://premaseem.wordpress.com/category/computers/design-patterns/
+*/
+public class StrawberryIceCream implements IceCream {
+
+ public StrawberryIceCream(Integer cost,Integer calories){
+ this.cost =cost;
+ this.calories =calories;
+ }
+
+ String brand = "";
+ Integer cost = 0;
+ Integer calories = 0;
+
+ public String toString () {
+ return this.getClass().getSimpleName() + " with Calories: " + getCalories() + " and cost: $" + getCost();
+ }
+
+ @Override
+ public Integer getCalories () {
+ return calories;
+ }
+
+ @Override
+ public Integer getCost () {
+ return cost;
+ }
+
+ @Override
+ public String getIceCreamName () {
+ return this.getClass().getSimpleName();
+ }
+}

patternBonus/src/com/premaseem/Client.java

@@ -1,13 +1,42 @@
 package com.premaseem;
 
+import com.premaseem.factory.PizzaBase;
+import com.premaseem.factory.PizzaFactory;
+
+import java.util.Scanner;
+
 /*
 @author: Aseem Jain
 @title: Design Patterns with Java 9
 @link: https://premaseem.wordpress.com/category/computers/design-patterns/
 @copyright: 2018 Packt Publication
 */
 public class Client {
- public static void main (String[] args) {
- System.out.println("Singleton cook example ");
+ public static void main(String[] args) {
+ Scanner scan = new Scanner(System.in);
+ int repeatRunFlag = 1;
+ while (repeatRunFlag == 1) {
+
+ System.out.println("This is the Client Main Factory Pattern ");
+
+ System.out.println("What kind of Pizza would you like to have ? ");
+ System.out.println("Enter veg for veg pizza ");
+ System.out.println("Enter non-veg for Non veg pizza ");
+ System.out.println("Enter max for Non Mexican pizza ");
+
+ String pizzaType = scan.next();
+ PizzaBase pizza = PizzaFactory.getPizza(pizzaType);
+
+ System.out.println("Your final order is");
+ System.out.println(pizza.getDescription());
+ System.out.println("Toal cost of order is " + pizza.getCost());
+ System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
+ System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
+ try{
+ repeatRunFlag = scan.nextInt();
+ }catch(Exception e){
+ repeatRunFlag = 0;
+ }
+ }
  }
 }

patternBonus/src/com/premaseem/factory/DefaultPizza.java

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+package com.premaseem.factory;
+
+public class DefaultPizza implements PizzaBase {
+
+@Override
+ public double getCost() {
+ // TODO Auto-generated method stub
+ return 5;
+ }
+
+@Override
+ public String getDescription() {
+ // TODO Auto-generated method stub
+ return "complementry pizza as order item is not available right now with us";
+ }
+
+}

patternBonus/src/com/premaseem/factory/MexicanPizza.java

@@ -0,0 +1,17 @@
+package com.premaseem.factory;
+
+public class MexicanPizza implements PizzaBase {
+
+@Override
+ public double getCost() {
+ // TODO Auto-generated method stub
+ return 13;
+ }
+
+@Override
+ public String getDescription() {
+ // TODO Auto-generated method stub
+ return "Mexican Pizza";
+ }
+
+}

patternBonus/src/com/premaseem/factory/NonVegPizza.java

@@ -0,0 +1,17 @@
+package com.premaseem.factory;
+
+public class NonVegPizza implements PizzaBase {
+
+@Override
+ public double getCost() {
+ // TODO Auto-generated method stub
+ return 24;
+ }
+
+@Override
+ public String getDescription() {
+ // TODO Auto-generated method stub
+ return "Non Veg Pizza";
+ }
+
+}

patternBonus/src/com/premaseem/factory/PizzaBase.java

@@ -0,0 +1,8 @@
+package com.premaseem.factory;
+
+public interface PizzaBase {
+
+double getCost();
+String getDescription();
+
+}

patternBonus/src/com/premaseem/factory/PizzaFactory.java

@@ -0,0 +1,23 @@
+package com.premaseem.factory;
+
+public class PizzaFactory {
+
+
+static public PizzaBase getPizza(String pizzaType){
+PizzaBase pizza = null;
+
+if(pizzaType.equalsIgnoreCase("veg")){
+pizza = new VegPizza();
+}else
+if(pizzaType.equalsIgnoreCase("nonveg")){
+pizza = new NonVegPizza();
+}else
+if(pizzaType.equalsIgnoreCase("mexican")){
+pizza = new MexicanPizza();
+}else{
+pizza = new DefaultPizza();
+}
+return pizza;
+}
+
+}

patternBonus/src/com/premaseem/factory/VegPizza.java

@@ -0,0 +1,17 @@
+package com.premaseem.factory;
+
+public class VegPizza implements PizzaBase {
+
+@Override
+ public double getCost() {
+ // TODO Auto-generated method stub
+ return 10;
+ }
+
+@Override
+ public String getDescription() {
+ // TODO Auto-generated method stub
+ return "Veg Pizza";
+ }
+
+}