Hi
I have to writ an new class for a project named "PizzaFride" in this
project are the 2 classes "Pizza" and PizzaFridg"
already given. Here are they:

/**
* Class that represents a Pizza.
*
* @author David Schuler
*
*/
public class Pizza {

    /**
    * Number of days the pizza is durable.
    */
    private int durableDays;

    /**

{
        return String.format("Pizza %s (noch %d Tage haltbar)", description,
                durableDays);
    }

    /**
    * Returns the number of days the pizza is durable.
    *
    * @return The number of days the pizza is durable
    */
    public int getDurableDays() {
        return durableDays;
    }

}

And the other class:

import java.util.ArrayList;
import java.util.List;

/**
* Class that represents an intelligent pizza fridge, which keeps
track of the
* durability of the contained pizzas.
*
* @author David Schuler
*
*/
public class PizzaFridge {

   private List<Pizza> contents = new ArrayList<Pizza>();

   /**
    * Add a pizza to the fridge.
    */
   public void addPizza(Pizza item) {
       contents.add(item);
   }

   /**
    * Prints the contents of the fridge to the System.out.
    */
   public void printContent() {
       if (contents.size() == 0) {
           System.out.println("Der Kühlschrank ist leer");
           return;
       }
       System.out.println("Der Kühlschrank enthält:");
       for (Pizza item : contents) {
           System.out.println("\t" + item);
       }
   }

   /**
    * @return The pizza with the lowest number of durable days.
    */
   public Pizza whichPizzaShouldIEat() {
       if (contents.size() == 0) {
           return null;
       }
       Pizza pizzaToConsume = contents.get(0);
       int min = pizzaToConsume.getDurableDays();
       for (Pizza item : contents) {
           if (min > item.getDurableDays())
           {
               pizzaToConsume = item;
               min = pizzaToConsume.getDurableDays();
               System.out.println("Diese Pizza sollte als nächstes
gegessen werden:");
               System.out.println(pizzaToConsume);
               preparePizza(pizzaToConsume);  // i have paste this
line
          }

       }
       return pizzaToConsume;

   }

   /**
    * If the pizza is contained in the fridge it automatically
removed from the
    * fridge and then prepared. Otherwise an error message is given.
    *
    * @param pizza
    *            The Pizza to prepare.
    */
   public void preparePizza(Pizza Pizza) {
       if (contents.contains(Pizza)) {
           contents.remove(Pizza);
           System.out.println("Diese Pizza wurde zubereitet:");
           System.out.println(Pizza);
       } else {
           System.out
                   .println("Diese Pizza ist nicht (mehr) im
Kühlschrank enthalten");
       }
   }

}

My task was it to write a new class with the method usePizzaFridge().
This class should add 3 new pizzas and  find out witch of this pizzas
should eat first. This pizza have to prepare.
My new class works only with th following text:

public class Joe
{

   private PizzaFridge PizzaFridge;
   private Pizza Pizza;

   public Joe()
   {

   }

   public void usePizzaFridge()
   {

       PizzaFridge = new PizzaFridge();
       Pizza = new Pizza (20, "Quattro Stagioni");
       PizzaFridge.addPizza(Pizza);
       Pizza = new Pizza (3, "Margherita");
       PizzaFridge.addPizza(Pizza);
       Pizza = new Pizza (17, "Pizza Napoli");
       PizzaFridge.addPizza(Pizza);
       PizzaFridge.printContent();
       PizzaFridge.whichPizzaShouldIEat();
       PizzaFridge.printContent();

   }

}

But if i change the durable days of the margherita pizza, for example
to 30 days the programm doesn't react and
prepare again the margherita pizza.
I hope someone can help me! thx!

(and sorry for my bad english)