1. Modello di progettazione del costruttore
2. Vantaggio di Builder DP
3. Utilizzo di Builder DP
4. UML di Builder DP
5. Esempio di costruttore DP

Lo dice Builder Pattern 'costruire un oggetto complesso partendo da oggetti semplici utilizzando un approccio passo passo'

Viene utilizzato principalmente quando l'oggetto non può essere creato in un unico passaggio come nella deserializzazione di un oggetto complesso.

Vantaggio del modello di progettazione del costruttore

I principali vantaggi di Builder Pattern sono i seguenti:

• Fornisce una chiara separazione tra la costruzione e la rappresentazione di un oggetto.
• Fornisce un migliore controllo sul processo di costruzione.
• Supporta la modifica della rappresentazione interna degli oggetti.

UML per esempio di modello di builder

Esempio di modello di progettazione del generatore

Per creare un semplice esempio di modello di progettazione del costruttore, è necessario seguire i 6 passaggi seguenti.

1. Crea l'interfaccia di imballaggio
2. Crea 2 classi astratte CD e Azienda
3. Creare 2 classi di implementazione dell'azienda: Sony e Samsung
4. Creare la classe CDType
5. Crea la classe CDBuilder
6. Crea la classe BuilderDemo

1) Creare l'interfaccia di imballaggio

 public interface Packing { public String pack(); public int price(); } 

2) Creare 2 classi astratte CD e Azienda

Creare un CD di classe astratta che implementerà l'interfaccia di imballaggio.

 public abstract class CD implements Packing{ public abstract String pack(); } 

 public abstract class Company extends CD{ public abstract int price(); } 

3) Creare 2 classi di implementazione dell'azienda: Sony e Samsung

 public class Sony extends Company{ @Override public int price(){ return 20; } @Override public String pack(){ return 'Sony CD'; } }//End of the Sony class. 

 public class Samsung extends Company { @Override public int price(){ return 15; } @Override public String pack(){ return 'Samsung CD'; } }//End of the Samsung class. 

4) Creare la classe CDType

 import java.util.ArrayList; import java.util.List; public class CDType { private List items=new ArrayList(); public void addItem(Packing packs) { items.add(packs); } public void getCost(){ for (Packing packs : items) { packs.price(); } } public void showItems(){ for (Packing packing : items){ System.out.print('CD name : '+packing.pack()); System.out.println(', Price : '+packing.price()); } } }//End of the CDType class. 

5) Creare la classe CDBuilder

 public class CDBuilder { public CDType buildSonyCD(){ CDType cds=new CDType(); cds.addItem(new Sony()); return cds; } public CDType buildSamsungCD(){ CDType cds=new CDType(); cds.addItem(new Samsung()); return cds; } }// End of the CDBuilder class. 

6) Crea la classe BuilderDemo

 public class BuilderDemo{ public static void main(String args[]){ CDBuilder cdBuilder=new CDBuilder(); CDType cdType1=cdBuilder.buildSonyCD(); cdType1.showItems(); CDType cdType2=cdBuilder.buildSamsungCD(); cdType2.showItems(); } } 

Output dell'esempio precedente

 CD name : Sony CD, Price : 20 CD name : Samsung CD, Price : 15 

Un altro esempio del mondo reale di Builder Pattern

UML per il modello di creazione:

Stiamo considerando un caso aziendale di pizza-hut dove possiamo ottenere diverse varietà di pizza e bibite fredde.

Pizza può essere una pizza Veg o una pizza Non Veg di diversi tipi (come pizza al formaggio, pizza alle cipolle, pizza al masala, ecc.) e sarà di 4 dimensioni, ovvero piccola, media, grande, extra-grande.

Bevanda fredda potranno essere di diversi tipi (come Pepsi, Coke, Dew, Sprite, Fanta, Maaza, Limca, Thums-up ecc.) e saranno di 3 dimensioni piccola, media, grande.

Esempio reale di modello di costruzione

Vediamo passo dopo passo l'esempio reale del Builder Design Pattern.

Passo 1: Crea un elemento dell'interfaccia che rappresenti la pizza e la bevanda fredda.

 public interface Item { public String name(); public String size(); public float price(); }// End of the interface Item. 

Passo 2: Crea una classe astratta Pizza che implementerà nell'interfaccia Item.

 public abstract class Pizza implements Item{ @Override public abstract float price(); } 

Passaggio 3: Crea una classe astratta ColdDrink che implementerà nell'interfaccia Item.

 public abstract class ColdDrink implements Item{ @Override public abstract float price(); } 

Passaggio 4: Crea una classe astratta VegPizza che si estenderà alla classe astratta Pizza.

 public abstract class VegPizza extends Pizza{ @Override public abstract float price(); @Override public abstract String name(); @Override public abstract String size(); }// End of the abstract class VegPizza. 

Passaggio 5: Crea una classe astratta NonVegPizza che si estenderà alla classe astratta Pizza.

 public abstract class NonVegPizza extends Pizza{ @Override public abstract float price(); @Override public abstract String name(); @Override public abstract String size(); }// End of the abstract class NonVegPizza. 

Passaggio 6: Ora creiamo le sottoclassi concrete SmallCheezePizza, MediumCheezePizza, LargeCheezePizza, ExtraLargeCheezePizza che si estenderanno alla classe astratta VegPizza.

 public class SmallCheezePizza extends VegPizza{ @Override public float price() { return 170.0f; } @Override public String name() { return 'Cheeze Pizza'; } @Override public String size() { return 'Small size'; } }// End of the SmallCheezePizza class. 

 public class MediumCheezePizza extends VegPizza{ @Override public float price() { return 220.f; } @Override public String name() { return &apos;Cheeze Pizza&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } }// End of the MediumCheezePizza class. File: LargeCheezePizza.java <pre> public class LargeCheezePizza extends VegPizza{ @Override public float price() { return 260.0f; } @Override public String name() { return &apos;Cheeze Pizza&apos;; } @Override public String size() { return &apos;Large Size&apos;; } }// End of the LargeCheezePizza class. </pre> File: ExtraLargeCheezePizza.java <pre> public class ExtraLargeCheezePizza extends VegPizza{ @Override public float price() { return 300.f; } @Override public String name() { return &apos;Cheeze Pizza&apos;; } @Override public String size() { return &apos;Extra-Large Size&apos;; } }// End of the ExtraLargeCheezePizza class. </pre> <p>Step 7: <b>Now, similarly create concrete sub-classes SmallOnionPizza, MediumOnionPizza, LargeOnionPizza, ExtraLargeOnionPizza that will extend to the abstract class VegPizza.</b> </p> File: SmallOnionPizza.java <pre> public class SmallOnionPizza extends VegPizza { @Override public float price() { return 120.0f; } @Override public String name() { return &apos;Onion Pizza&apos;; } @Override public String size() { return &apos;Small Size&apos;; } }// End of the SmallOnionPizza class. </pre> File: MediumOnionPizza.java <pre> public class MediumOnionPizza extends VegPizza { @Override public float price() { return 150.0f; } @Override public String name() { return &apos;Onion Pizza&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } }// End of the MediumOnionPizza class. </pre> File: LargeOnionPizza.java <pre> public class LargeOnionPizza extends VegPizza{ @Override public float price() { return 180.0f; } @Override public String name() { return &apos;Onion Pizza&apos;; } @Override public String size() { return &apos;Large size&apos;; } }// End of the LargeOnionPizza class. </pre> File: ExtraLargeOnionPizza.java <pre> public class ExtraLargeOnionPizza extends VegPizza { @Override public float price() { return 200.0f; } @Override public String name() { return &apos;Onion Pizza&apos;; } @Override public String size() { return &apos;Extra-Large Size&apos;; } }// End of the ExtraLargeOnionPizza class </pre> <p>Step 8: <b>Now, similarly create concrete sub-classes SmallMasalaPizza, MediumMasalaPizza, LargeMasalaPizza, ExtraLargeMasalaPizza that will extend to the abstract class VegPizza.</b> </p> File: SmallMasalaPizza.java <pre> public class SmallMasalaPizza extends VegPizza{ @Override public float price() { return 100.0f; } @Override public String name() { return &apos;Masala Pizza&apos;; } @Override public String size() { return &apos;Samll Size&apos;; } }// End of the SmallMasalaPizza class </pre> File: MediumMasalaPizza.java <pre> public class MediumMasalaPizza extends VegPizza { @Override public float price() { return 120.0f; } @Override public String name() { return &apos;Masala Pizza&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } </pre> File: LargeMasalaPizza.java <pre> public class LargeMasalaPizza extends VegPizza{ @Override public float price() { return 150.0f; } @Override public String name() { return &apos;Masala Pizza&apos;; } @Override public String size() { return &apos;Large Size&apos;; } } //End of the LargeMasalaPizza class </pre> File: ExtraLargeMasalaPizza.java <pre> public class ExtraLargeMasalaPizza extends VegPizza { @Override public float price() { return 180.0f; } @Override public String name() { return &apos;Masala Pizza&apos;; } @Override public String size() { return &apos;Extra-Large Size&apos;; } }// End of the ExtraLargeMasalaPizza class </pre> <p>Step 9: <b>Now, create concrete sub-classes SmallNonVegPizza, MediumNonVegPizza, LargeNonVegPizza, ExtraLargeNonVegPizza that will extend to the abstract class NonVegPizza.</b> </p> File: SmallNonVegPizza.java <pre> public class SmallNonVegPizza extends NonVegPizza { @Override public float price() { return 180.0f; } @Override public String name() { return &apos;Non-Veg Pizza&apos;; } @Override public String size() { return &apos;Samll Size&apos;; } }// End of the SmallNonVegPizza class </pre> File: MediumNonVegPizza.java <pre> public class MediumNonVegPizza extends NonVegPizza{ @Override public float price() { return 200.0f; } @Override public String name() { return &apos;Non-Veg Pizza&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } </pre> File: LargeNonVegPizza.java <pre> public class LargeNonVegPizza extends NonVegPizza{ @Override public float price() { return 220.0f; } @Override public String name() { return &apos;Non-Veg Pizza&apos;; } @Override public String size() { return &apos;Large Size&apos;; } }// End of the LargeNonVegPizza class </pre> File: ExtraLargeNonVegPizza.java <pre> public class ExtraLargeNonVegPizza extends NonVegPizza { @Override public float price() { return 250.0f; } @Override public String name() { return &apos;Non-Veg Pizza&apos;; } @Override public String size() { return &apos;Extra-Large Size&apos;; } } // End of the ExtraLargeNonVegPizza class </pre> <p>Step 10: <b>Now, create two abstract classes Pepsi and Coke that will extend abstract class ColdDrink. </b> </p> File: Pepsi.java <pre> public abstract class Pepsi extends ColdDrink { @Override public abstract String name(); @Override public abstract String size(); @Override public abstract float price(); }// End of the Pepsi class </pre> File: Coke.java <pre> public abstract class Coke extends ColdDrink { @Override public abstract String name(); @Override public abstract String size(); @Override public abstract float price(); }// End of the Coke class <p>Step 11: <b>Now, create concrete sub-classes SmallPepsi, MediumPepsi, LargePepsi that will extend to the abstract class Pepsi.</b> </p> File: SmallPepsi.java <pre> public class SmallPepsi extends Pepsi{ @Override public String name() { return &apos;300 ml Pepsi&apos;; } @Override public float price() { return 25.0f; } @Override public String size() { return &apos;Small Size&apos;; } }// End of the SmallPepsi class </pre> File: MediumPepsi.java <pre> public class MediumPepsi extends Pepsi { @Override public String name() { return &apos;500 ml Pepsi&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } @Override public float price() { return 35.0f; } }// End of the MediumPepsi class </pre> File: LargePepsi.java <pre> public class LargePepsi extends Pepsi{ @Override public String name() { return &apos;750 ml Pepsi&apos;; } @Override public String size() { return &apos;Large Size&apos;; } @Override public float price() { return 50.0f; } }// End of the LargePepsi class </pre> <p>Step 12: <b>Now, create concrete sub-classes SmallCoke, MediumCoke, LargeCoke that will extend to the abstract class Coke.</b> </p> File: SmallCoke.java <pre> public class SmallCoke extends Coke{ @Override public String name() { return &apos;300 ml Coke&apos;; } @Override public String size() { return &apos;Small Size&apos;; } @Override public float price() { return 25.0f; } }// End of the SmallCoke class </pre> File: MediumCoke.java <pre> public class MediumCoke extends Coke{ @Override public String name() { return &apos;500 ml Coke&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } @Override public float price() { return 35.0f; } }// End of the MediumCoke class </pre> File: LargeCoke.java <pre> public class LargeCoke extends Coke { @Override public String name() { return &apos;750 ml Coke&apos;; } @Override public String size() { return &apos;Large Size&apos;; } @Override public float price() { return 50.0f; } }// End of the LargeCoke class <p>Step 13: <b>Create an OrderedItems class that are having Item objects defined above.</b> </p> File: OrderedItems.java <pre> import java.util.ArrayList; import java.util.List; public class OrderedItems { List items=new ArrayList(); public void addItems(Item item){ items.add(item); } public float getCost(){ float cost=0.0f; for (Item item : items) { cost+=item.price(); } return cost; } public void showItems(){ for (Item item : items) { System.out.println(&apos;Item is:&apos; +item.name()); System.out.println(&apos;Size is:&apos; +item.size()); System.out.println(&apos;Price is: &apos; +item.price()); } } }// End of the OrderedItems class </pre> <p>Step 14: <b>Create an OrderBuilder class that will be responsible to create the objects of OrderedItems class.</b> </p> File: OrdereBuilder.java <pre> import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class OrderBuilder { public OrderedItems preparePizza() throws IOException{ OrderedItems itemsOrder=new OrderedItems(); BufferedReader br =new BufferedReader(new InputStreamReader(System.in)); System.out.println(&apos; Enter the choice of Pizza &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Veg-Pizza &apos;); System.out.println(&apos; 2. Non-Veg Pizza &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int pizzaandcolddrinkchoice=Integer.parseInt(br.readLine()); switch(pizzaandcolddrinkchoice) { case 1:{ System.out.println(&apos;You ordered Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos; Enter the types of Veg-Pizza &apos;); System.out.println(&apos;------------------------------&apos;); System.out.println(&apos; 1.Cheeze Pizza &apos;); System.out.println(&apos; 2.Onion Pizza &apos;); System.out.println(&apos; 3.Masala Pizza &apos;); System.out.println(&apos; 4.Exit &apos;); System.out.println(&apos;------------------------------&apos;); int vegpizzachoice=Integer.parseInt(br.readLine()); switch(vegpizzachoice) { case 1: { System.out.println(&apos;You ordered Cheeze Pizza&apos;); System.out.println(&apos;Enter the cheeze pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Cheeze Pizza &apos;); System.out.println(&apos; 2. Medium Cheeze Pizza &apos;); System.out.println(&apos; 3. Large Cheeze Pizza &apos;); System.out.println(&apos; 4. Extra-Large Cheeze Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int cheezepizzasize=Integer.parseInt(br.readLine()); switch(cheezepizzasize) { case 1: itemsOrder.addItems(new SmallCheezePizza()); break; case 2: itemsOrder.addItems(new MediumCheezePizza()); break; case 3: itemsOrder.addItems(new LargeCheezePizza()); break; case 4: itemsOrder.addItems(new ExtraLargeCheezePizza()); break; case 2: { System.out.println(&apos;You ordered Onion Pizza&apos;); System.out.println(&apos;Enter the Onion pizza size&apos;); System.out.println(&apos;----------------------------------&apos;); System.out.println(&apos; 1. Small Onion Pizza &apos;); System.out.println(&apos; 2. Medium Onion Pizza &apos;); System.out.println(&apos; 3. Large Onion Pizza &apos;); System.out.println(&apos; 4. Extra-Large Onion Pizza &apos;); System.out.println(&apos;----------------------------------&apos;); int onionpizzasize=Integer.parseInt(br.readLine()); switch(onionpizzasize) { case 1: itemsOrder.addItems(new SmallOnionPizza()); break; case 2: itemsOrder.addItems(new MediumOnionPizza()); break; case 3: itemsOrder.addItems(new LargeOnionPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeOnionPizza()); break; } } break; case 3: { System.out.println(&apos;You ordered Masala Pizza&apos;); System.out.println(&apos;Enter the Masala pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Masala Pizza &apos;); System.out.println(&apos; 2. Medium Masala Pizza &apos;); System.out.println(&apos; 3. Large Masala Pizza &apos;); System.out.println(&apos; 4. Extra-Large Masala Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int masalapizzasize=Integer.parseInt(br.readLine()); switch(masalapizzasize) { case 1: itemsOrder.addItems(new SmallMasalaPizza()); break; case 2: itemsOrder.addItems(new MediumMasalaPizza()); break; case 3: itemsOrder.addItems(new LargeMasalaPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeMasalaPizza()); break; } } break; } } break;// Veg- pizza choice completed. case 2: { System.out.println(&apos;You ordered Non-Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos;Enter the Non-Veg pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Non-Veg Pizza &apos;); System.out.println(&apos; 2. Medium Non-Veg Pizza &apos;); System.out.println(&apos; 3. Large Non-Veg Pizza &apos;); System.out.println(&apos; 4. Extra-Large Non-Veg Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int nonvegpizzasize=Integer.parseInt(br.readLine()); switch(nonvegpizzasize) { case 1: itemsOrder.addItems(new SmallNonVegPizza()); break; case 2: itemsOrder.addItems(new MediumNonVegPizza()); break; case 3: itemsOrder.addItems(new LargeNonVegPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeNonVegPizza()); break; } } break; default: { break; } }//end of main Switch //continued?.. System.out.println(&apos; Enter the choice of ColdDrink &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Pepsi &apos;); System.out.println(&apos; 2. Coke &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int coldDrink=Integer.parseInt(br.readLine()); switch (coldDrink) { case 1: { System.out.println(&apos;You ordered Pepsi &apos;); System.out.println(&apos;Enter the Pepsi Size &apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Pepsi &apos;); System.out.println(&apos; 2. Medium Pepsi &apos;); System.out.println(&apos; 3. Large Pepsi &apos;); System.out.println(&apos;------------------------&apos;); int pepsisize=Integer.parseInt(br.readLine()); switch(pepsisize) { case 1: itemsOrder.addItems(new SmallPepsi()); break; case 2: itemsOrder.addItems(new MediumPepsi()); break; case 3: itemsOrder.addItems(new LargePepsi()); break; } } break; case 2: { System.out.println(&apos;You ordered Coke&apos;); System.out.println(&apos;Enter the Coke Size&apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Coke &apos;); System.out.println(&apos; 2. Medium Coke &apos;); System.out.println(&apos; 3. Large Coke &apos;); System.out.println(&apos; 4. Extra-Large Coke &apos;); System.out.println(&apos;------------------------&apos;); int cokesize=Integer.parseInt(br.readLine()); switch(cokesize) { case 1: itemsOrder.addItems(new SmallCoke()); break; case 2: itemsOrder.addItems(new MediumCoke()); break; case 3: itemsOrder.addItems(new LargeCoke()); break; } } break; default: { break; } }//End of the Cold-Drink switch return itemsOrder; } //End of the preparePizza() method </pre> <p>Step 15: <b>Create a BuilderDemo class that will use the OrderBuilder class.</b> </p> File: Prototype.java <pre> import java.io.IOException; public class BuilderDemo { public static void main(String[] args) throws IOException { // TODO code application logic here OrderBuilder builder=new OrderBuilder(); OrderedItems orderedItems=builder.preparePizza(); orderedItems.showItems(); System.out.println(&apos;
&apos;); System.out.println(&apos;Total Cost : &apos;+ orderedItems.getCost()); } }// End of the BuilderDemo class </pre> <hr> download this Builder Pattern Example <h4>Output</h4>  </pre></pre>

 public class ExtraLargeCheezePizza extends VegPizza{ @Override public float price() { return 300.f; } @Override public String name() { return 'Cheeze Pizza'; } @Override public String size() { return 'Extra-Large Size'; } }// End of the ExtraLargeCheezePizza class. 

Passaggio 7: Ora, allo stesso modo, crea sottoclassi concrete SmallOnionPizza, MediumOnionPizza, LargeOnionPizza, ExtraLargeOnionPizza che si estenderanno alla classe astratta VegPizza.

 public class SmallOnionPizza extends VegPizza { @Override public float price() { return 120.0f; } @Override public String name() { return 'Onion Pizza'; } @Override public String size() { return 'Small Size'; } }// End of the SmallOnionPizza class. 

 public class MediumOnionPizza extends VegPizza { @Override public float price() { return 150.0f; } @Override public String name() { return 'Onion Pizza'; } @Override public String size() { return 'Medium Size'; } }// End of the MediumOnionPizza class. 

 public class LargeOnionPizza extends VegPizza{ @Override public float price() { return 180.0f; } @Override public String name() { return 'Onion Pizza'; } @Override public String size() { return 'Large size'; } }// End of the LargeOnionPizza class. 

 public class ExtraLargeOnionPizza extends VegPizza { @Override public float price() { return 200.0f; } @Override public String name() { return 'Onion Pizza'; } @Override public String size() { return 'Extra-Large Size'; } }// End of the ExtraLargeOnionPizza class 

Passaggio 8: Ora, in modo simile, crea le sottoclassi concrete SmallMasalaPizza, MediumMasalaPizza, LargeMasalaPizza, ExtraLargeMasalaPizza che si estenderanno alla classe astratta VegPizza.

 public class SmallMasalaPizza extends VegPizza{ @Override public float price() { return 100.0f; } @Override public String name() { return 'Masala Pizza'; } @Override public String size() { return 'Samll Size'; } }// End of the SmallMasalaPizza class 

 public class MediumMasalaPizza extends VegPizza { @Override public float price() { return 120.0f; } @Override public String name() { return 'Masala Pizza'; } @Override public String size() { return 'Medium Size'; } 

 public class LargeMasalaPizza extends VegPizza{ @Override public float price() { return 150.0f; } @Override public String name() { return 'Masala Pizza'; } @Override public String size() { return 'Large Size'; } } //End of the LargeMasalaPizza class 

 public class ExtraLargeMasalaPizza extends VegPizza { @Override public float price() { return 180.0f; } @Override public String name() { return 'Masala Pizza'; } @Override public String size() { return 'Extra-Large Size'; } }// End of the ExtraLargeMasalaPizza class 

Passaggio 9: Ora creiamo le sottoclassi concrete SmallNonVegPizza, MediumNonVegPizza, LargeNonVegPizza, ExtraLargeNonVegPizza che si estenderanno alla classe astratta NonVegPizza.

 public class SmallNonVegPizza extends NonVegPizza { @Override public float price() { return 180.0f; } @Override public String name() { return 'Non-Veg Pizza'; } @Override public String size() { return 'Samll Size'; } }// End of the SmallNonVegPizza class 

 public class MediumNonVegPizza extends NonVegPizza{ @Override public float price() { return 200.0f; } @Override public String name() { return 'Non-Veg Pizza'; } @Override public String size() { return 'Medium Size'; } 

 public class LargeNonVegPizza extends NonVegPizza{ @Override public float price() { return 220.0f; } @Override public String name() { return 'Non-Veg Pizza'; } @Override public String size() { return 'Large Size'; } }// End of the LargeNonVegPizza class 

 public class ExtraLargeNonVegPizza extends NonVegPizza { @Override public float price() { return 250.0f; } @Override public String name() { return 'Non-Veg Pizza'; } @Override public String size() { return 'Extra-Large Size'; } } // End of the ExtraLargeNonVegPizza class 

Passaggio 10: Ora crea due classi astratte Pepsi e Coca-Cola che estenderanno la classe astratta ColdDrink.

 public abstract class Pepsi extends ColdDrink { @Override public abstract String name(); @Override public abstract String size(); @Override public abstract float price(); }// End of the Pepsi class 

 public abstract class Coke extends ColdDrink { @Override public abstract String name(); @Override public abstract String size(); @Override public abstract float price(); }// End of the Coke class <p>Step 11: <b>Now, create concrete sub-classes SmallPepsi, MediumPepsi, LargePepsi that will extend to the abstract class Pepsi.</b> </p> File: SmallPepsi.java <pre> public class SmallPepsi extends Pepsi{ @Override public String name() { return &apos;300 ml Pepsi&apos;; } @Override public float price() { return 25.0f; } @Override public String size() { return &apos;Small Size&apos;; } }// End of the SmallPepsi class </pre> File: MediumPepsi.java <pre> public class MediumPepsi extends Pepsi { @Override public String name() { return &apos;500 ml Pepsi&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } @Override public float price() { return 35.0f; } }// End of the MediumPepsi class </pre> File: LargePepsi.java <pre> public class LargePepsi extends Pepsi{ @Override public String name() { return &apos;750 ml Pepsi&apos;; } @Override public String size() { return &apos;Large Size&apos;; } @Override public float price() { return 50.0f; } }// End of the LargePepsi class </pre> <p>Step 12: <b>Now, create concrete sub-classes SmallCoke, MediumCoke, LargeCoke that will extend to the abstract class Coke.</b> </p> File: SmallCoke.java <pre> public class SmallCoke extends Coke{ @Override public String name() { return &apos;300 ml Coke&apos;; } @Override public String size() { return &apos;Small Size&apos;; } @Override public float price() { return 25.0f; } }// End of the SmallCoke class </pre> File: MediumCoke.java <pre> public class MediumCoke extends Coke{ @Override public String name() { return &apos;500 ml Coke&apos;; } @Override public String size() { return &apos;Medium Size&apos;; } @Override public float price() { return 35.0f; } }// End of the MediumCoke class </pre> File: LargeCoke.java <pre> public class LargeCoke extends Coke { @Override public String name() { return &apos;750 ml Coke&apos;; } @Override public String size() { return &apos;Large Size&apos;; } @Override public float price() { return 50.0f; } }// End of the LargeCoke class <p>Step 13: <b>Create an OrderedItems class that are having Item objects defined above.</b> </p> File: OrderedItems.java <pre> import java.util.ArrayList; import java.util.List; public class OrderedItems { List items=new ArrayList(); public void addItems(Item item){ items.add(item); } public float getCost(){ float cost=0.0f; for (Item item : items) { cost+=item.price(); } return cost; } public void showItems(){ for (Item item : items) { System.out.println(&apos;Item is:&apos; +item.name()); System.out.println(&apos;Size is:&apos; +item.size()); System.out.println(&apos;Price is: &apos; +item.price()); } } }// End of the OrderedItems class </pre> <p>Step 14: <b>Create an OrderBuilder class that will be responsible to create the objects of OrderedItems class.</b> </p> File: OrdereBuilder.java <pre> import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class OrderBuilder { public OrderedItems preparePizza() throws IOException{ OrderedItems itemsOrder=new OrderedItems(); BufferedReader br =new BufferedReader(new InputStreamReader(System.in)); System.out.println(&apos; Enter the choice of Pizza &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Veg-Pizza &apos;); System.out.println(&apos; 2. Non-Veg Pizza &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int pizzaandcolddrinkchoice=Integer.parseInt(br.readLine()); switch(pizzaandcolddrinkchoice) { case 1:{ System.out.println(&apos;You ordered Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos; Enter the types of Veg-Pizza &apos;); System.out.println(&apos;------------------------------&apos;); System.out.println(&apos; 1.Cheeze Pizza &apos;); System.out.println(&apos; 2.Onion Pizza &apos;); System.out.println(&apos; 3.Masala Pizza &apos;); System.out.println(&apos; 4.Exit &apos;); System.out.println(&apos;------------------------------&apos;); int vegpizzachoice=Integer.parseInt(br.readLine()); switch(vegpizzachoice) { case 1: { System.out.println(&apos;You ordered Cheeze Pizza&apos;); System.out.println(&apos;Enter the cheeze pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Cheeze Pizza &apos;); System.out.println(&apos; 2. Medium Cheeze Pizza &apos;); System.out.println(&apos; 3. Large Cheeze Pizza &apos;); System.out.println(&apos; 4. Extra-Large Cheeze Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int cheezepizzasize=Integer.parseInt(br.readLine()); switch(cheezepizzasize) { case 1: itemsOrder.addItems(new SmallCheezePizza()); break; case 2: itemsOrder.addItems(new MediumCheezePizza()); break; case 3: itemsOrder.addItems(new LargeCheezePizza()); break; case 4: itemsOrder.addItems(new ExtraLargeCheezePizza()); break; case 2: { System.out.println(&apos;You ordered Onion Pizza&apos;); System.out.println(&apos;Enter the Onion pizza size&apos;); System.out.println(&apos;----------------------------------&apos;); System.out.println(&apos; 1. Small Onion Pizza &apos;); System.out.println(&apos; 2. Medium Onion Pizza &apos;); System.out.println(&apos; 3. Large Onion Pizza &apos;); System.out.println(&apos; 4. Extra-Large Onion Pizza &apos;); System.out.println(&apos;----------------------------------&apos;); int onionpizzasize=Integer.parseInt(br.readLine()); switch(onionpizzasize) { case 1: itemsOrder.addItems(new SmallOnionPizza()); break; case 2: itemsOrder.addItems(new MediumOnionPizza()); break; case 3: itemsOrder.addItems(new LargeOnionPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeOnionPizza()); break; } } break; case 3: { System.out.println(&apos;You ordered Masala Pizza&apos;); System.out.println(&apos;Enter the Masala pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Masala Pizza &apos;); System.out.println(&apos; 2. Medium Masala Pizza &apos;); System.out.println(&apos; 3. Large Masala Pizza &apos;); System.out.println(&apos; 4. Extra-Large Masala Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int masalapizzasize=Integer.parseInt(br.readLine()); switch(masalapizzasize) { case 1: itemsOrder.addItems(new SmallMasalaPizza()); break; case 2: itemsOrder.addItems(new MediumMasalaPizza()); break; case 3: itemsOrder.addItems(new LargeMasalaPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeMasalaPizza()); break; } } break; } } break;// Veg- pizza choice completed. case 2: { System.out.println(&apos;You ordered Non-Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos;Enter the Non-Veg pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Non-Veg Pizza &apos;); System.out.println(&apos; 2. Medium Non-Veg Pizza &apos;); System.out.println(&apos; 3. Large Non-Veg Pizza &apos;); System.out.println(&apos; 4. Extra-Large Non-Veg Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int nonvegpizzasize=Integer.parseInt(br.readLine()); switch(nonvegpizzasize) { case 1: itemsOrder.addItems(new SmallNonVegPizza()); break; case 2: itemsOrder.addItems(new MediumNonVegPizza()); break; case 3: itemsOrder.addItems(new LargeNonVegPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeNonVegPizza()); break; } } break; default: { break; } }//end of main Switch //continued?.. System.out.println(&apos; Enter the choice of ColdDrink &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Pepsi &apos;); System.out.println(&apos; 2. Coke &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int coldDrink=Integer.parseInt(br.readLine()); switch (coldDrink) { case 1: { System.out.println(&apos;You ordered Pepsi &apos;); System.out.println(&apos;Enter the Pepsi Size &apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Pepsi &apos;); System.out.println(&apos; 2. Medium Pepsi &apos;); System.out.println(&apos; 3. Large Pepsi &apos;); System.out.println(&apos;------------------------&apos;); int pepsisize=Integer.parseInt(br.readLine()); switch(pepsisize) { case 1: itemsOrder.addItems(new SmallPepsi()); break; case 2: itemsOrder.addItems(new MediumPepsi()); break; case 3: itemsOrder.addItems(new LargePepsi()); break; } } break; case 2: { System.out.println(&apos;You ordered Coke&apos;); System.out.println(&apos;Enter the Coke Size&apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Coke &apos;); System.out.println(&apos; 2. Medium Coke &apos;); System.out.println(&apos; 3. Large Coke &apos;); System.out.println(&apos; 4. Extra-Large Coke &apos;); System.out.println(&apos;------------------------&apos;); int cokesize=Integer.parseInt(br.readLine()); switch(cokesize) { case 1: itemsOrder.addItems(new SmallCoke()); break; case 2: itemsOrder.addItems(new MediumCoke()); break; case 3: itemsOrder.addItems(new LargeCoke()); break; } } break; default: { break; } }//End of the Cold-Drink switch return itemsOrder; } //End of the preparePizza() method </pre> <p>Step 15: <b>Create a BuilderDemo class that will use the OrderBuilder class.</b> </p> File: Prototype.java <pre> import java.io.IOException; public class BuilderDemo { public static void main(String[] args) throws IOException { // TODO code application logic here OrderBuilder builder=new OrderBuilder(); OrderedItems orderedItems=builder.preparePizza(); orderedItems.showItems(); System.out.println(&apos;
&apos;); System.out.println(&apos;Total Cost : &apos;+ orderedItems.getCost()); } }// End of the BuilderDemo class </pre> <hr> download this Builder Pattern Example <h4>Output</h4>  </pre>

 public class MediumPepsi extends Pepsi { @Override public String name() { return '500 ml Pepsi'; } @Override public String size() { return 'Medium Size'; } @Override public float price() { return 35.0f; } }// End of the MediumPepsi class 

 public class LargePepsi extends Pepsi{ @Override public String name() { return '750 ml Pepsi'; } @Override public String size() { return 'Large Size'; } @Override public float price() { return 50.0f; } }// End of the LargePepsi class 

Passaggio 12: Ora creiamo le sottoclassi concrete SmallCoke, MediumCoke, LargeCoke che si estenderanno alla classe astratta Coke.

 public class SmallCoke extends Coke{ @Override public String name() { return '300 ml Coke'; } @Override public String size() { return 'Small Size'; } @Override public float price() { return 25.0f; } }// End of the SmallCoke class 

 public class MediumCoke extends Coke{ @Override public String name() { return '500 ml Coke'; } @Override public String size() { return 'Medium Size'; } @Override public float price() { return 35.0f; } }// End of the MediumCoke class 

 public class LargeCoke extends Coke { @Override public String name() { return &apos;750 ml Coke&apos;; } @Override public String size() { return &apos;Large Size&apos;; } @Override public float price() { return 50.0f; } }// End of the LargeCoke class <p>Step 13: <b>Create an OrderedItems class that are having Item objects defined above.</b> </p> File: OrderedItems.java <pre> import java.util.ArrayList; import java.util.List; public class OrderedItems { List items=new ArrayList(); public void addItems(Item item){ items.add(item); } public float getCost(){ float cost=0.0f; for (Item item : items) { cost+=item.price(); } return cost; } public void showItems(){ for (Item item : items) { System.out.println(&apos;Item is:&apos; +item.name()); System.out.println(&apos;Size is:&apos; +item.size()); System.out.println(&apos;Price is: &apos; +item.price()); } } }// End of the OrderedItems class </pre> <p>Step 14: <b>Create an OrderBuilder class that will be responsible to create the objects of OrderedItems class.</b> </p> File: OrdereBuilder.java <pre> import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class OrderBuilder { public OrderedItems preparePizza() throws IOException{ OrderedItems itemsOrder=new OrderedItems(); BufferedReader br =new BufferedReader(new InputStreamReader(System.in)); System.out.println(&apos; Enter the choice of Pizza &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Veg-Pizza &apos;); System.out.println(&apos; 2. Non-Veg Pizza &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int pizzaandcolddrinkchoice=Integer.parseInt(br.readLine()); switch(pizzaandcolddrinkchoice) { case 1:{ System.out.println(&apos;You ordered Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos; Enter the types of Veg-Pizza &apos;); System.out.println(&apos;------------------------------&apos;); System.out.println(&apos; 1.Cheeze Pizza &apos;); System.out.println(&apos; 2.Onion Pizza &apos;); System.out.println(&apos; 3.Masala Pizza &apos;); System.out.println(&apos; 4.Exit &apos;); System.out.println(&apos;------------------------------&apos;); int vegpizzachoice=Integer.parseInt(br.readLine()); switch(vegpizzachoice) { case 1: { System.out.println(&apos;You ordered Cheeze Pizza&apos;); System.out.println(&apos;Enter the cheeze pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Cheeze Pizza &apos;); System.out.println(&apos; 2. Medium Cheeze Pizza &apos;); System.out.println(&apos; 3. Large Cheeze Pizza &apos;); System.out.println(&apos; 4. Extra-Large Cheeze Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int cheezepizzasize=Integer.parseInt(br.readLine()); switch(cheezepizzasize) { case 1: itemsOrder.addItems(new SmallCheezePizza()); break; case 2: itemsOrder.addItems(new MediumCheezePizza()); break; case 3: itemsOrder.addItems(new LargeCheezePizza()); break; case 4: itemsOrder.addItems(new ExtraLargeCheezePizza()); break; case 2: { System.out.println(&apos;You ordered Onion Pizza&apos;); System.out.println(&apos;Enter the Onion pizza size&apos;); System.out.println(&apos;----------------------------------&apos;); System.out.println(&apos; 1. Small Onion Pizza &apos;); System.out.println(&apos; 2. Medium Onion Pizza &apos;); System.out.println(&apos; 3. Large Onion Pizza &apos;); System.out.println(&apos; 4. Extra-Large Onion Pizza &apos;); System.out.println(&apos;----------------------------------&apos;); int onionpizzasize=Integer.parseInt(br.readLine()); switch(onionpizzasize) { case 1: itemsOrder.addItems(new SmallOnionPizza()); break; case 2: itemsOrder.addItems(new MediumOnionPizza()); break; case 3: itemsOrder.addItems(new LargeOnionPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeOnionPizza()); break; } } break; case 3: { System.out.println(&apos;You ordered Masala Pizza&apos;); System.out.println(&apos;Enter the Masala pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Masala Pizza &apos;); System.out.println(&apos; 2. Medium Masala Pizza &apos;); System.out.println(&apos; 3. Large Masala Pizza &apos;); System.out.println(&apos; 4. Extra-Large Masala Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int masalapizzasize=Integer.parseInt(br.readLine()); switch(masalapizzasize) { case 1: itemsOrder.addItems(new SmallMasalaPizza()); break; case 2: itemsOrder.addItems(new MediumMasalaPizza()); break; case 3: itemsOrder.addItems(new LargeMasalaPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeMasalaPizza()); break; } } break; } } break;// Veg- pizza choice completed. case 2: { System.out.println(&apos;You ordered Non-Veg Pizza&apos;); System.out.println(&apos;

&apos;); System.out.println(&apos;Enter the Non-Veg pizza size&apos;); System.out.println(&apos;------------------------------------&apos;); System.out.println(&apos; 1. Small Non-Veg Pizza &apos;); System.out.println(&apos; 2. Medium Non-Veg Pizza &apos;); System.out.println(&apos; 3. Large Non-Veg Pizza &apos;); System.out.println(&apos; 4. Extra-Large Non-Veg Pizza &apos;); System.out.println(&apos;------------------------------------&apos;); int nonvegpizzasize=Integer.parseInt(br.readLine()); switch(nonvegpizzasize) { case 1: itemsOrder.addItems(new SmallNonVegPizza()); break; case 2: itemsOrder.addItems(new MediumNonVegPizza()); break; case 3: itemsOrder.addItems(new LargeNonVegPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeNonVegPizza()); break; } } break; default: { break; } }//end of main Switch //continued?.. System.out.println(&apos; Enter the choice of ColdDrink &apos;); System.out.println(&apos;============================&apos;); System.out.println(&apos; 1. Pepsi &apos;); System.out.println(&apos; 2. Coke &apos;); System.out.println(&apos; 3. Exit &apos;); System.out.println(&apos;============================&apos;); int coldDrink=Integer.parseInt(br.readLine()); switch (coldDrink) { case 1: { System.out.println(&apos;You ordered Pepsi &apos;); System.out.println(&apos;Enter the Pepsi Size &apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Pepsi &apos;); System.out.println(&apos; 2. Medium Pepsi &apos;); System.out.println(&apos; 3. Large Pepsi &apos;); System.out.println(&apos;------------------------&apos;); int pepsisize=Integer.parseInt(br.readLine()); switch(pepsisize) { case 1: itemsOrder.addItems(new SmallPepsi()); break; case 2: itemsOrder.addItems(new MediumPepsi()); break; case 3: itemsOrder.addItems(new LargePepsi()); break; } } break; case 2: { System.out.println(&apos;You ordered Coke&apos;); System.out.println(&apos;Enter the Coke Size&apos;); System.out.println(&apos;------------------------&apos;); System.out.println(&apos; 1. Small Coke &apos;); System.out.println(&apos; 2. Medium Coke &apos;); System.out.println(&apos; 3. Large Coke &apos;); System.out.println(&apos; 4. Extra-Large Coke &apos;); System.out.println(&apos;------------------------&apos;); int cokesize=Integer.parseInt(br.readLine()); switch(cokesize) { case 1: itemsOrder.addItems(new SmallCoke()); break; case 2: itemsOrder.addItems(new MediumCoke()); break; case 3: itemsOrder.addItems(new LargeCoke()); break; } } break; default: { break; } }//End of the Cold-Drink switch return itemsOrder; } //End of the preparePizza() method </pre> <p>Step 15: <b>Create a BuilderDemo class that will use the OrderBuilder class.</b> </p> File: Prototype.java <pre> import java.io.IOException; public class BuilderDemo { public static void main(String[] args) throws IOException { // TODO code application logic here OrderBuilder builder=new OrderBuilder(); OrderedItems orderedItems=builder.preparePizza(); orderedItems.showItems(); System.out.println(&apos;
&apos;); System.out.println(&apos;Total Cost : &apos;+ orderedItems.getCost()); } }// End of the BuilderDemo class </pre> <hr> download this Builder Pattern Example <h4>Output</h4>  

Passaggio 14: Crea una classe OrderBuilder che sarà responsabile della creazione degli oggetti della classe OrderedItems.

 import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class OrderBuilder { public OrderedItems preparePizza() throws IOException{ OrderedItems itemsOrder=new OrderedItems(); BufferedReader br =new BufferedReader(new InputStreamReader(System.in)); System.out.println(' Enter the choice of Pizza '); System.out.println('============================'); System.out.println(' 1. Veg-Pizza '); System.out.println(' 2. Non-Veg Pizza '); System.out.println(' 3. Exit '); System.out.println('============================'); int pizzaandcolddrinkchoice=Integer.parseInt(br.readLine()); switch(pizzaandcolddrinkchoice) { case 1:{ System.out.println('You ordered Veg Pizza'); System.out.println('

'); System.out.println(' Enter the types of Veg-Pizza '); System.out.println('------------------------------'); System.out.println(' 1.Cheeze Pizza '); System.out.println(' 2.Onion Pizza '); System.out.println(' 3.Masala Pizza '); System.out.println(' 4.Exit '); System.out.println('------------------------------'); int vegpizzachoice=Integer.parseInt(br.readLine()); switch(vegpizzachoice) { case 1: { System.out.println('You ordered Cheeze Pizza'); System.out.println('Enter the cheeze pizza size'); System.out.println('------------------------------------'); System.out.println(' 1. Small Cheeze Pizza '); System.out.println(' 2. Medium Cheeze Pizza '); System.out.println(' 3. Large Cheeze Pizza '); System.out.println(' 4. Extra-Large Cheeze Pizza '); System.out.println('------------------------------------'); int cheezepizzasize=Integer.parseInt(br.readLine()); switch(cheezepizzasize) { case 1: itemsOrder.addItems(new SmallCheezePizza()); break; case 2: itemsOrder.addItems(new MediumCheezePizza()); break; case 3: itemsOrder.addItems(new LargeCheezePizza()); break; case 4: itemsOrder.addItems(new ExtraLargeCheezePizza()); break; case 2: { System.out.println('You ordered Onion Pizza'); System.out.println('Enter the Onion pizza size'); System.out.println('----------------------------------'); System.out.println(' 1. Small Onion Pizza '); System.out.println(' 2. Medium Onion Pizza '); System.out.println(' 3. Large Onion Pizza '); System.out.println(' 4. Extra-Large Onion Pizza '); System.out.println('----------------------------------'); int onionpizzasize=Integer.parseInt(br.readLine()); switch(onionpizzasize) { case 1: itemsOrder.addItems(new SmallOnionPizza()); break; case 2: itemsOrder.addItems(new MediumOnionPizza()); break; case 3: itemsOrder.addItems(new LargeOnionPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeOnionPizza()); break; } } break; case 3: { System.out.println('You ordered Masala Pizza'); System.out.println('Enter the Masala pizza size'); System.out.println('------------------------------------'); System.out.println(' 1. Small Masala Pizza '); System.out.println(' 2. Medium Masala Pizza '); System.out.println(' 3. Large Masala Pizza '); System.out.println(' 4. Extra-Large Masala Pizza '); System.out.println('------------------------------------'); int masalapizzasize=Integer.parseInt(br.readLine()); switch(masalapizzasize) { case 1: itemsOrder.addItems(new SmallMasalaPizza()); break; case 2: itemsOrder.addItems(new MediumMasalaPizza()); break; case 3: itemsOrder.addItems(new LargeMasalaPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeMasalaPizza()); break; } } break; } } break;// Veg- pizza choice completed. case 2: { System.out.println('You ordered Non-Veg Pizza'); System.out.println('

'); System.out.println('Enter the Non-Veg pizza size'); System.out.println('------------------------------------'); System.out.println(' 1. Small Non-Veg Pizza '); System.out.println(' 2. Medium Non-Veg Pizza '); System.out.println(' 3. Large Non-Veg Pizza '); System.out.println(' 4. Extra-Large Non-Veg Pizza '); System.out.println('------------------------------------'); int nonvegpizzasize=Integer.parseInt(br.readLine()); switch(nonvegpizzasize) { case 1: itemsOrder.addItems(new SmallNonVegPizza()); break; case 2: itemsOrder.addItems(new MediumNonVegPizza()); break; case 3: itemsOrder.addItems(new LargeNonVegPizza()); break; case 4: itemsOrder.addItems(new ExtraLargeNonVegPizza()); break; } } break; default: { break; } }//end of main Switch //continued?.. System.out.println(' Enter the choice of ColdDrink '); System.out.println('============================'); System.out.println(' 1. Pepsi '); System.out.println(' 2. Coke '); System.out.println(' 3. Exit '); System.out.println('============================'); int coldDrink=Integer.parseInt(br.readLine()); switch (coldDrink) { case 1: { System.out.println('You ordered Pepsi '); System.out.println('Enter the Pepsi Size '); System.out.println('------------------------'); System.out.println(' 1. Small Pepsi '); System.out.println(' 2. Medium Pepsi '); System.out.println(' 3. Large Pepsi '); System.out.println('------------------------'); int pepsisize=Integer.parseInt(br.readLine()); switch(pepsisize) { case 1: itemsOrder.addItems(new SmallPepsi()); break; case 2: itemsOrder.addItems(new MediumPepsi()); break; case 3: itemsOrder.addItems(new LargePepsi()); break; } } break; case 2: { System.out.println('You ordered Coke'); System.out.println('Enter the Coke Size'); System.out.println('------------------------'); System.out.println(' 1. Small Coke '); System.out.println(' 2. Medium Coke '); System.out.println(' 3. Large Coke '); System.out.println(' 4. Extra-Large Coke '); System.out.println('------------------------'); int cokesize=Integer.parseInt(br.readLine()); switch(cokesize) { case 1: itemsOrder.addItems(new SmallCoke()); break; case 2: itemsOrder.addItems(new MediumCoke()); break; case 3: itemsOrder.addItems(new LargeCoke()); break; } } break; default: { break; } }//End of the Cold-Drink switch return itemsOrder; } //End of the preparePizza() method 

Passaggio 15: Crea una classe BuilderDemo che utilizzerà la classe OrderBuilder.

 import java.io.IOException; public class BuilderDemo { public static void main(String[] args) throws IOException { // TODO code application logic here OrderBuilder builder=new OrderBuilder(); OrderedItems orderedItems=builder.preparePizza(); orderedItems.showItems(); System.out.println('
'); System.out.println('Total Cost : '+ orderedItems.getCost()); } }// End of the BuilderDemo class 

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