Шаблон "Декоратор" - примери

Пример 1

Window.java

public interface Window {
 public void Draw();
 public String getDescription();
}

SimpleWindow.java

public class SimpleWindow implements Window {
 public void Draw() {
  //TODO
  return;
 }
 public String getDescription() {
  return "Simple Window";
 }
}

WindowDecorator.java

public abstract class WindowDecorator implements Window {
 protected Window WindowToBeDecorated;
 
 public abstract void Draw();
 public abstract String getDescription();
 public WindowDecorator(Window WindowToBeDecorated) {
  this.WindowToBeDecorated = WindowToBeDecorated;
 }
}

VerticalScrollDecorator.java

public class VerticalScrollDecorator extends WindowDecorator {
 @Override
 public void Draw() {
  //TODO
  return;
 }
 
 @Override
 public String getDescription() {
  return WindowToBeDecorated.getDescription()+" which has been decorated with vertical scrollbar";
 }
 
 public VerticalScrollDecorator(Window WindowToBeDecorated) {
  super(WindowToBeDecorated);
 }
 
}

HorizontalScrollDecorator.java

public class HorizontalScrollDecorator extends WindowDecorator {
 @Override
 public void Draw() {
  //TODO
  return ;
 }
 
 @Override
 public String getDescription() {
  return WindowToBeDecorated.getDescription() + " which has been decorated with horizontal scrollbar";
 }
 
 public HorizontalScrollDecorator(Window WindowToBeDecorated) {
  super(WindowToBeDecorated);
 }
}

BorderDecorator.java

public class BorderDecorator extends WindowDecorator {
 @Override
 public void Draw() {
  //TODO
  return ;
 }
 
 @Override
 public String getDescription() {
  return WindowToBeDecorated.getDescription() + " which has borders";
 }
  
 public BorderDecorator(Window WindowToBeDecorated) {
  super(WindowToBeDecorated);
 }
}

DecoratorTest.java

public class DecoratorTest {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  Window win = new SimpleWindow();
  System.out.println(win.getDescription());
  
  win = new VerticalScrollDecorator(new SimpleWindow());
  System.out.println(win.getDescription());
  
  win = new HorizontalScrollDecorator(new SimpleWindow());
  System.out.println(win.getDescription());
  
  win = new VerticalScrollDecorator(new HorizontalScrollDecorator(new SimpleWindow()));
  System.out.println(win.getDescription());
  
  win = new BorderDecorator(new SimpleWindow());
  System.out.println(win.getDescription());
  
  win = new VerticalScrollDecorator(new BorderDecorator(new SimpleWindow()));
  System.out.println(win.getDescription());
 }

}

Пример 2

UML

Calculator.java

package code.lalev.Calculator;

public interface Calculator {
 public String Dobavi(String a, String b); //Добавя две числа
 public String Umnoji(String a, String b); //Умножава две числа
 public String Izvadi(String a, String b); //Изважда b от а 
 public String Razdeli(String a, String b); //Дели a на b
 public void Zapameti(String a);
 public String Vystanovi();
}

ProstCalculator.java

package code.lalev.Calculator;

public class ProstCalculator implements Calculator {
 Double memory;
 
 public ProstCalculator() {
  memory = 0d;
 }
 
 //Добавя две числа
 public String Dobavi(String a, String b) {
  
  //Конвертира a от String в Double
  Double newa = Double.parseDouble(a);
  Double newb = Double.parseDouble(b);
  Double result = newa+newb;
  return result.toString();
  
 }
 
 //Умножава две числа
 public String Umnoji(String a, String b) {
    //Конвертира a от String в Double
  Double newa = Double.parseDouble(a);
  Double newb = Double.parseDouble(b);
  Double result = newa*newb;
  return result.toString();
  
 }
 
 //Изважда b от а
 public String Izvadi(String a, String b) {
  
  //Конвертира a от String в Double
  Double newa = Double.parseDouble(a);
  Double newb = Double.parseDouble(b);
  Double result = newa-newb;
  return result.toString();
 }
 
 //Дели a на b
 public String Razdeli(String a, String b) {
  
  //Конвертира a от String в Double
  Double newa = Double.parseDouble(a);
  Double newb = Double.parseDouble(b);
  Double result = newa/newb;
  return result.toString();  
 }
 
 //Дели a на b
 public void Zapameti(String a) {
  memory = Double.parseDouble(a);
 }
 
 //Дели a на b
 public String Vystanovi() {
  return memory.toString();
 }

 
 
}

ObshtCalculator.java

package code.lalev.Calculator;

public abstract class ObshtCalculator implements Calculator {
  protected Calculator calc;
 
  public ObshtCalculator(Calculator calc) {
   this.calc = calc;
  }
}

DvoichenCalculator.java

package code.lalev.Calculator;

public class DvoichenCalculator extends ObshtCalculator {

 public DvoichenCalculator(Calculator calc) {
  super(calc);
 }
 
 @Override
 public String Dobavi(String a, String b) {
  Integer newa = Integer.parseInt(a, 2);
  Integer newb = Integer.parseInt(b, 2);
  return Integer.toBinaryString(
    (int) Double.parseDouble(
      calc.Dobavi(newa.toString(), 
         newb.toString())));
 
 }

 @Override
 public String Umnoji(String a, String b) {
  Integer newa = Integer.parseInt(a, 2);
  Integer newb = Integer.parseInt(b, 2);
  return Integer.toBinaryString(
    (int) Double.parseDouble(
      calc.Umnoji(newa.toString(), 
         newb.toString())));
 }

 @Override
 public String Izvadi(String a, String b) {
  Integer newa = Integer.parseInt(a, 2);
  Integer newb = Integer.parseInt(b, 2);
  return Integer.toBinaryString(
    (int) Double.parseDouble(
      calc.Izvadi(newa.toString(), 
         newb.toString())));
 }

 @Override
 public String Razdeli(String a, String b) {
  return "NaN";
 }

 @Override
 public void Zapameti(String a) {
  Integer newa = Integer.parseInt(a, 2);
  calc.Zapameti(newa.toString());
 }

 @Override
 public String Vystanovi() {
  return Integer.toBinaryString(
    Integer.parseInt(
      calc.Vystanovi().toString()));
 }

}