#structural pattern

package com.designpattern.structuralpattern; /**  *  * @author Shaiful Islam(palash)  */ class CPU{     public void freeze(){}     public void jump(long position){}     public void execute(){} } class Memory{     public void load(long position, byte[] data){} } class HardDrive{     public byte[] read(long lba, int size){return null;} } class Computer{     private CPU cpu;     private Memory memory;     private HardDrive hardDrive;     public Computer(){         this.cpu = new CPU();         this.memory = new Memory();         this.hardDrive = new HardDrive();     }         public void startComputer(){         cpu.freeze();         memory.load(1, null);         cpu.jump(1);         cpu.execute();     }     } public class FacadePattern {     public static void main(String[] args){         Computer facade = new Computer();         facade.startComputer();     } }

package com.designpattern.structuralpattern; /**  *  * @author 154166  */ public class DecoratorPattern {     public static void main(String[] args){         SimpleWindow simpleWindow = new SimpleWindow();         //simpleWindow.draw();         //System.out.println(simpleWindow.getDescription());                         //Window decoratedWindow = new HorizontalScrollBarDecorator(simpleWindow);         Window decoratedWindow = new HorizontalScrollBarDecorator (new VerticalScrollBarDecorator(new SimpleWindow()));         System.out.println(decoratedWindow.getDescription());     } } interface Window{     public void draw();     public String getDescription(); } class SimpleWindow implements Window{         @Override     public void draw(){         System.out.println("Printing something");     }         @Override     public String getDescription(){         return "simple window";     } } // abstract decorator class - note that it implements Window abstract class WindowDecorator implements Window{     protected Window decoratedWindow;     public WindowDecorator(Window decorateWindow){         this.decoratedWindow = decorateWindow;     }         // delegation     @Override     public void draw(){         decoratedWindow.draw();     }         // delegation     @Override     public String getDescription(){         return decoratedWindow.getDescription();     } } class VerticalScrollBarDecorator extends WindowDecorator{     public VerticalScrollBarDecorator(Window decoratedWindow){         super(decoratedWindow);     }         @Override     public void draw(){         decoratedWindow.draw();         drawHorizontalScrollBar();     }         private void drawHorizontalScrollBar(){         System.out.println("draw horizontal scroll bar");     }         @Override     public String getDescription(){         return decoratedWindow.getDescription() + ", including vertical scrollbars";     } } class HorizontalScrollBarDecorator extends WindowDecorator{     public HorizontalScrollBarDecorator(Window decoratedWindow){         super(decoratedWindow);     }         @Override     public void draw(){         decoratedWindow.draw();         drawHorizontalScrollBar();     }         private void drawHorizontalScrollBar(){         System.out.println("drawing the horizontal scroll bar");     }         @Override     public String getDescription(){         return decoratedWindow.getDescription() + ", including horizontal scrollbars";     }    }

package com.designpattern.structuralpattern; import java.util.List; import java.util.ArrayList; // component interface Graphic{     public void print(); } // composite class CompositeGraphic implements Graphic{     private List<Graphic> childGraphics = new ArrayList<Graphic>();         @Override     public void print() {         for(Graphic graphic : childGraphics){             graphic.print();         }     }         public void add(Graphic graphic){         childGraphics.add(graphic);     }         public void remove(Graphic graphic){         childGraphics.remove(graphic);     }     } // leaf class Ellipse implements Graphic{     @Override     public void print() {         System.out.println("Ellipse");     }     } // client public class CompositePattern {     public static void main(String[] args){         Ellipse ellipse1 = new Ellipse();         Ellipse ellipse2 = new Ellipse();         Ellipse ellipse3 = new Ellipse();         Ellipse ellipse4 = new Ellipse();                 //composite         CompositeGraphic graphic = new CompositeGraphic();         CompositeGraphic graphic1 = new CompositeGraphic();         CompositeGraphic graphic2 = new CompositeGraphic();                 graphic1.add(ellipse1);         graphic1.add(ellipse2);         graphic1.add(ellipse3);                 graphic2.add(ellipse4);                 graphic.add(ellipse1);         graphic.add(ellipse2);                 graphic.print();     } }

/*  * To change this template, choose Tools | Templates  * and open the template in the editor.  */ package com.designpattern.structuralpattern; /**  *  * @author palash  */ public class BridgePattern {     public static void main(String[] args){         // first example         Fan fan = new Fan();         fan.switchOn();         Bulb bulb = new Bulb();         bulb.switchOff();                 // second example         Shape[] shapes = new Shape[]{             new CircleShape(1, 2, 3, new DrawingAPI1()),             new CircleShape(5, 7, 11, new DrawingAPI2()),         };         for(Shape shape : shapes){             shape.resizeByPercentage(2.5);             shape.draw();         }     } } // first example interface Switch{     public void switchOn();     public void switchOff(); } class Fan implements Switch{     @Override     public void switchOn() {         System.out.println("Fan's switch on");     }     @Override     public void switchOff() {         System.out.println("Fan's switch off");     }   } class Bulb implements Switch{     @Override     public void switchOn() {         System.out.println("Bulb's switch on");     }     @Override     public void switchOff() {         System.out.println("Bulb's switch off");     }     } /////////////////////////////////////// // second example //implementor interface DrawingAPI{     public void drawCircle(double x, double y, double radius); } // concreteImplementor class DrawingAPI1 implements DrawingAPI{     @Override     public void drawCircle(double x, double y, double radius) {         System.out.printf("API1.circle at %f:%f radius %f\n", x, y, radius);     } } // concreteImplementor class DrawingAPI2 implements DrawingAPI{     @Override     public void drawCircle(double x, double y, double radius) {         System.out.printf("API1.circle at %f:%f radius %f\n", x, y, radius);     }    } // abstraction abstract class Shape{     protected DrawingAPI drawingAPI;     protected Shape(DrawingAPI drawingAPI){         this.drawingAPI = drawingAPI;     }         public abstract void draw();     public abstract void resizeByPercentage(double pct); } class CircleShape extends Shape{     private double x,y,radius;         public CircleShape(double x, double y, double radius, DrawingAPI drawingAPI){         super(drawingAPI);         this.x = x;  this.y = y;  this.radius = radius;     }     @Override     public void draw() {         drawingAPI.drawCircle(x, y, radius);     }     @Override     public void resizeByPercentage(double pct) {         radius *= pct;     }     }

package com.designpattern.structuralpattern; /**  *  * @author palash  */ public class AdapterPattern {     public static void main(String[] args){               // class adapter pattern by inheritance         RectangularPlugClass clientPlug = new RectangularPlugClass("5amp", "15map");         System.out.println(clientPlug.getPower());                 // object adapter pattern by composition         RectangularPlugObject clientPlugObj = new RectangularPlugObject("7amp", "20amp");         System.out.println(clientPlugObj.getPower());     } } // class adapter pattern class CylindericalSocketClass{     public String supply(String cylinStem1, String cylinStem2){         System.out.println("Power...");         return cylinStem1 + " and " + cylinStem2 + " power supply from class adapter pattern";     } } class RectangularAdapterClass extends CylindericalSocketClass{     public String adapt(String rectaStem1, String rectaStem2){         String cylinStem1 = rectaStem1;         String cylinStem2 = rectaStem2;         return supply(cylinStem1, cylinStem2);     } } class RectangularPlugClass{     private String rectaStem1;     private String rectaStem2;     public RectangularPlugClass(String param1, String param2){         this.rectaStem1 = param1;         this.rectaStem2 = param2;     }         public String getPower(){         RectangularAdapterClass adapter = new RectangularAdapterClass();         String power = adapter.adapt(rectaStem1, rectaStem2);         return power;     } } /////////////////////////////////////////////// // Object adapter pattern class CylindericalSocketObject{     public String supply(String cylinStem1, String cylinStem2){         System.out.println("Power...");         return cylinStem1 + " and " + cylinStem2 + " power supply from object adapter pattern";     } } class RectangularAdapterObject{     private CylindericalSocketObject socket;         public String adapt(String rectaStem1, String rectaStem2){         socket = new CylindericalSocketObject();         String cylinStem1 = rectaStem1;         String cylinStem2 = rectaStem2;         return socket.supply(cylinStem1, cylinStem2);     } } class RectangularPlugObject{     private String rectaStem1;     private String rectaStem2;     public RectangularPlugObject(String param1, String param2){         this.rectaStem1 = param1;         this.rectaStem2 = param2;     }         public String getPower(){         RectangularAdapterObject adapter = new RectangularAdapterObject();         String power = adapter.adapt(rectaStem1, rectaStem2);         return power;     } }

Decorator pattern: Decorator describes how to add responsibilities to objects dynamically. Decorator is a structural pattern that composes object recursively to allow an open-ended number of additional responsibilities.