装点器模式（网站借鉴的）

package com.decorator;
/**
 * 面包类
 * @author Administrator
 *
 */
public class Bread extends Ingredient {

    private String description ;

    public Bread(String desc){

              this.description=desc ;

    }

    public String getDescription(){

              return description ;

    }       

    public double getCost(){

              return 2.48 ;

    }       

}


package com.decorator;

public class Celery extends Decorator{

    public Celery(Ingredient igd){

              super(igd);

    }

    public String getDescription(){

              String base = ingredient.getDescription();

              return base +"\n"+"Decrocated with Celery !";

    }

    public double getCost(){

              double basePrice = ingredient.getCost();

              double celeryPrice =0.6;

              return      basePrice + celeryPrice ;

    }

}


package com.decorator;

public abstract class Decorator extends Ingredient {

    Ingredient ingredient ;

    public Decorator(Ingredient igd){

             this.ingredient = igd;     

    }       

    public abstract String getDescription();

    public abstract double getCost();

}


package com.decorator;

public class GreenGrocery extends Decorator{

    public GreenGrocery (Ingredient igd){

              super(igd);

    }

    public String getDescription(){

              String base = ingredient.getDescription();

              return base +"\n"+"Decrocated with GreenGrocery  !";

    }

    public double getCost(){

              double basePrice = ingredient.getCost();

              double greenGroceryPrice = 0.4;

              return        basePrice + greenGroceryPrice ;

    }

}


package com.decorator;
/**
 * 原料类 
 * @author Administrator
 *
 */
public abstract class Ingredient {

         public abstract String getDescription();

         public abstract double getCost();    

         public void printDescription(){        

                   System.out.println(" Name      "+ this.getDescription());

                   System.out.println(" Price RMB "+ this.getCost());

         }

}



package com.decorator;

public class Mutton extends Decorator{

    public Mutton(Ingredient igd){

              super(igd);

    }

    public String getDescription(){

              String base = ingredient.getDescription();

              return base +"\n"+"Decrocated with Mutton !";

    }

    public double getCost(){

              double basePrice = ingredient.getCost();

              double muttonPrice = 2.3;

              return        basePrice + muttonPrice ;

    }

}


package com.decorator;

public class Pork extends Decorator{

    public Pork(Ingredient igd){

              super(igd);

    }

    public String getDescription(){

              String base = ingredient.getDescription();

              return base +"\n"+"Decrocated with Pork !";

    }

    public double getCost(){

              double basePrice = ingredient.getCost();

              double porkPrice = 1.8;

              return        basePrice + porkPrice ;

    }

}


package com.decorator;

public class DecoratorTest {
	public static void main(String[] args)
	{
		   Ingredient compound = new Mutton(new Celery(new Bread("Master24's Bread")));              

           compound.printDescription();

          

           compound = new Celery(new GreenGrocery(new Bread("Bread with milk")));    

           compound.printDescription();

          

           compound = new Mutton(new Pork(new Bread("Bread with cheese")));

           compound.printDescription();
	}

}