Merge pull request #56 from KunwarVikas/stackandqueue

Java Design Patterns

com/javadevjournal/design/creational/prototype/Circle.java

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+package javadevjournal.design.creational.prototype;
+
+/**
+ * @author Kunwar
+ */
+public class Circle extends Shape {
+
+    public Circle() {
+        type = "Circle";
+    }
+
+    @Override
+    public void draw() {
+        System.out.println("Circle's draw() method.");
+    }
+}

com/javadevjournal/design/creational/prototype/PrototypePatternDemo.java

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+package javadevjournal.design.creational.prototype;
+
+/**
+ * @author Kunwar
+ */
+public class PrototypePatternDemo {
+    public static void main(String[] args) {
+        ShapeCache.loadCache();
+
+        Shape clonedShape = (Shape) ShapeCache.getShape("1");
+        System.out.println("Shape : " + clonedShape.getType());
+
+        Shape clonedShape2 = (Shape) ShapeCache.getShape("2");
+        System.out.println("Shape : " + clonedShape2.getType());
+
+        Shape clonedShape3 = (Shape) ShapeCache.getShape("3");
+        System.out.println("Shape : " + clonedShape3.getType());
+    }
+}

com/javadevjournal/design/creational/prototype/Rectangle.java

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+package javadevjournal.design.creational.prototype;
+
+/**
+ * @author Kunwar
+ */
+public class Rectangle extends Shape {
+
+    public Rectangle() {
+        type = "Rectangle";
+    }
+
+    @Override
+    public void draw() {
+        System.out.println("Rectangle's draw() method.");
+    }
+}

com/javadevjournal/design/creational/prototype/Shape.java

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+package javadevjournal.design.creational.prototype;
+
+/**
+ * @author Kunwar
+ */
+public abstract class Shape implements Cloneable {
+    private String id;
+    protected String type;
+
+    abstract void draw();
+
+    public String getType() {
+        return type;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    /**
+     * Use Object class's Clone() method to do the cloning.
+     *
+     * @return
+     */
+    public Object clone() {
+        Object cloneObject = null;
+        try {
+            cloneObject = super.clone();
+        } catch (CloneNotSupportedException e) {
+            System.out.println("cloning failed");
+            e.printStackTrace();
+        }
+        return cloneObject;
+    }
+}

com/javadevjournal/design/creational/prototype/ShapeCache.java

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+package javadevjournal.design.creational.prototype;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author Kunwar
+ */
+
+public class ShapeCache {
+    private static Map<String, Shape> shapeMap = new HashMap<String, Shape>();
+
+    /**
+     * Return cloned object of Shape class implementing classes.
+     *
+     * @param shapeId
+     * @return
+     */
+    public static Shape getShape(String shapeId) {
+        Shape toBeClonedShape = shapeMap.get(shapeId);
+        return (Shape) toBeClonedShape.clone();
+    }
+
+
+    /**
+     * In real-world applications, the loading of details will be from a Database.
+     * We are using a HaspMap to demonstrate the same behavior.
+     */
+    public static void loadCache() {
+        Circle circle = new Circle();
+        circle.setId("1");
+        shapeMap.put(circle.getId(), circle);
+
+        Square square = new Square();
+        square.setId("2");
+        shapeMap.put(square.getId(), square);
+
+        Rectangle rectangle = new Rectangle();
+        rectangle.setId("3");
+        shapeMap.put(rectangle.getId(), rectangle);
+    }
+}

com/javadevjournal/design/creational/prototype/Square.java

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+package javadevjournal.design.creational.prototype;
+
+/**
+ * @author Kunwar
+ */
+public class Square extends Shape {
+
+    public Square() {
+        type = "Square";
+    }
+
+    @Override
+    public void draw() {
+        System.out.println("Square's draw() method.");
+    }
+}

com/javadevjournal/design/structural/decorator/Circle.java

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+package javadevjournal.design.structural.decorator;
+
+/**
+ * @author Kunwar
+ */
+public class Circle implements Shape {
+
+	@Override
+	public void drawShape() {
+		System.out.println("The shape is: Circle");
+	}
+}

com/javadevjournal/design/structural/decorator/DecoratorPatternDemo.java

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+package javadevjournal.design.structural.decorator;// DecoratorPatternDemo.java
+
+/**
+ * @author Kunwar
+ */
+public class DecoratorPatternDemo {
+
+	public static void main(String[] args) {
+		// Creating objects of Shape interface
+		Shape circle = new Circle();
+		Shape rectangle = new Rectangle();
+
+		// Creating objects of decorated classes
+		Shape redCircle = new RedShapeDecorator(new Circle());
+		Shape redRectangle = new RedShapeDecorator(new Rectangle());
+
+		System.out.println("Circle with normal fill");
+		circle.drawShape();
+
+		System.out.println("Rectangle with normal fill");
+		rectangle.drawShape();
+
+		System.out.println("\nCircle of red fill");
+		redCircle.drawShape();
+
+		System.out.println("\nRectangle of red fill");
+		redRectangle.drawShape();
+	}
+}

com/javadevjournal/design/structural/decorator/Rectangle.java

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+package javadevjournal.design.structural.decorator;// Class 1
+
+/**
+ * @author Kunwar
+ */
+public class Rectangle implements Shape {
+
+	@Override
+	public void drawShape() {
+		System.out.println("The shape is: Rectangle");
+	}
+}

com/javadevjournal/design/structural/decorator/RedShapeDecorator.java

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+package javadevjournal.design.structural.decorator;
+
+/**
+ * @author Kunwar
+ */
+public class RedShapeDecorator extends ShapeDecorator {
+
+	public RedShapeDecorator(Shape decoratedShape) {
+		super(decoratedShape);
+	}
+
+	@Override
+	public void drawShape() {
+		decoratedShape.drawShape();
+		//additional method to change the behavior of the shape object
+		shapeFill(decoratedShape);
+	}
+
+	/**
+	 * This method will change the behavior of the shape object at runtime.
+	 *
+	 * @param decoratedShape
+	 */
+	private void shapeFill(Shape decoratedShape) {
+		System.out.println("Shape Fill color: Red");
+	}
+}

com/javadevjournal/design/structural/decorator/Shape.java

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+package javadevjournal.design.structural.decorator;
+
+/**
+ * @author Kunwar
+ */
+public interface Shape {
+	void drawShape();
+}

com/javadevjournal/design/structural/decorator/ShapeDecorator.java

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+package javadevjournal.design.structural.decorator;
+
+/**
+ * @author Kunwar
+ */
+public abstract class ShapeDecorator implements Shape {
+
+	//protected object of Shape Interface.
+	protected Shape decoratedShape;
+
+	public ShapeDecorator(Shape decoratedShape) {
+		this.decoratedShape = decoratedShape;
+	}
+
+	//calling the drawShape method on decoratedShape
+	public void drawShape() {
+		decoratedShape.drawShape();
+	}
+}

com/javadevjournal/design/structural/facade/FacadePatternClient.java

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+package javadevjournal.design.structural.facade;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+/**
+ * @author Kunwar
+ */
+public class FacadePatternClient {
+    private static int choice;
+
+    public static void main(String args[]) throws NumberFormatException, IOException {
+        do {
+            System.out.print("========= Mobile Shop ============ \n");
+            System.out.print("1. IPHONE.              \n");
+            System.out.print("2. SAMSUNG.              \n");
+            System.out.print("3. NOKIA.                 \n");
+            System.out.print("4. Exit.                   \n");
+            System.out.print("Enter your choice: ");
+
+            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+            choice = Integer.parseInt(br.readLine());
+            ShopKeeper shopKeeper = new ShopKeeper();
+
+            switch (choice) {
+                case 1: {
+                    shopKeeper.iphonePhoneSale();
+                }
+                break;
+                case 2: {
+                    shopKeeper.samsungPhoneSale();
+                }
+                break;
+                case 3: {
+                    shopKeeper.nokiaPhoneSale();
+                }
+                break;
+                default: {
+                    System.out.println("Nothing You purchased");
+                }
+                return;
+            }
+        } while (choice != 4);
+    }
+}  

com/javadevjournal/design/structural/facade/IMobileShop.java

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+package javadevjournal.design.structural.facade;
+
+/**
+ * @author Kunwar
+ */
+public interface IMobileShop {
+    /**
+     * Mobile Model Number
+     */
+    public void getMobileModelNumber();
+
+    /**
+     * Mobile Price
+     */
+    public void getMobilePrice();
+}  

com/javadevjournal/design/structural/facade/Iphone.java

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+package javadevjournal.design.structural.facade;
+
+/**
+ * @author Kunwar
+ */
+public class Iphone implements IMobileShop {
+    @Override
+    public void getMobileModelNumber() {
+        System.out.println("The model is: IPhone 13");
+    }
+
+    @Override
+    public void getMobilePrice() {
+        System.out.println("The price is: 75000INR ");
+    }
+} 

com/javadevjournal/design/structural/facade/Nokia.java

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+package javadevjournal.design.structural.facade;
+
+/**
+ * @author Kunwar
+ */
+public class Nokia implements IMobileShop {
+    @Override
+    public void getMobileModelNumber() {
+        System.out.println("The model is: Nokia 1100");
+    }
+
+    @Override
+    public void getMobilePrice() {
+        System.out.println("The price is: 1500INR ");
+    }
+}

com/javadevjournal/design/structural/facade/Samsung.java

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+package javadevjournal.design.structural.facade;
+
+/**
+ * @author Kunwar
+ */
+public class Samsung implements IMobileShop {
+    @Override
+    public void getMobileModelNumber() {
+        System.out.println("The model is: Galaxy 11");
+    }
+
+    @Override
+    public void getMobilePrice() {
+        System.out.println("The price is: 85000INR ");
+    }
+}  

com/javadevjournal/design/structural/facade/ShopKeeper.java

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+package javadevjournal.design.structural.facade;
+
+/**
+ * @author Kunwar
+ */
+public class ShopKeeper {
+    private IMobileShop iphone;
+    private IMobileShop samsung;
+    private IMobileShop nokia;
+
+    /**
+     * no args constructor
+     */
+    public ShopKeeper() {
+        iphone = new Iphone();
+        samsung = new Samsung();
+        nokia = new Nokia();
+    }
+
+    public void iphonePhoneSale() {
+        iphone.getMobileModelNumber();
+        iphone.getMobilePrice();
+    }
+
+    public void samsungPhoneSale() {
+        samsung.getMobileModelNumber();
+        samsung.getMobilePrice();
+    }
+
+    public void nokiaPhoneSale() {
+        nokia.getMobileModelNumber();
+        nokia.getMobilePrice();
+    }
+}