Webshop.java

class Article {
	int artCode;
	float price;
	int stock;
	
	void buy (int n) {
		stock += n;
	}

	void sell (int n) {
		stock -= n;
	}

	boolean available () {
		return stock > 0;
	}

	String getDescription () {
		return "ArtNr. " + artCode + " €" + price;
	}

	Article (int ac, float p) {
		artCode = ac;
		price = p;
		stock = 0;
	}
}

class Book extends Article {
	String author;
	String title;

	String getDescription () {
		return getKind() + " '" + title + "' von " +
			author + "; " + super.getDescription();
	}

	String getKind () {
		return "Buch";
	}

	Book (int ac, float p, String a, String t) {
		super(ac, p);
		author = a;
		title = t;
	}

	Book (int ac, String a, String t) {  // construct a free book
		this(ac, 0, a, t);
		}
}

class PrintedBook extends Book {

	String getKind () {
		return "Print-Ausgabe";
	}

	PrintedBook (int ac, float p, String a, String t) {
		super(ac, p, a, t);
	}
}

class EBook extends Book {

	String getKind () {
		return "E-Book";
	}

	EBook (int ac, float p, String a, String t) {
		super(ac, p, a, t);
	}
}

class Audio extends Article{
	String albumTitle;
	String artist;
	int trackNum;
	int duration;
	
	String getDescription(){
		return getKind() + " '"+ albumTitle + "' von " + artist +
			"; "+ trackNum + " Lieder, " + duration +" Gesamtlänge. "
			+ super.getDescription();
		
	}
	String getKind(){
		return "Audio";
	}
	Audio(String aT, String a, int tN, int d, float p, int ac){
	super(ac, p);
	albumTitle = aT;
	artist = a;
	trackNum = tN;
	
	}
	
}

class MP3Album extends Audio{
	int bitrate;
	
	String getKind(){
		return "MP3-Album";
	}
	
	MP3Album(String aT, String a, int tN, int d, int br, float p, int ac){
		super(aT, a, tN,d,p,ac);
		bitrate = br;
		
	
	}
	
}

class CDAlbum extends Audio{
	String  cover;
	
	String  getKind(){
		return "CD-Album";
	}
	
	CDAlbum(String aT,String a, int tN, int d, String c,float p, int ac){
		super(aT, a, tN, d,p,ac);
		cover = c;
	}
	
	
	
}

// brauche eventuell eine WArenkorbklasse, oder eine Methode. Muss noch überlegen.
public class WebShop {
	
	static void printInvoice (Article[] cart) {
		float total = 0;
		Out.println("Rechnung");
		Out.println("--------");
		for (Article a: cart) {
			if (a != null) {
				String s = a.getDescription();
				Out.println(s);
				total += a.price;
			}
			}
		Out.println("===============");
		Out.printf("Summe: €%7.2f\n", total);
	}

   public static void main (String[] args) {
		Article[] cart = new Article[10];
      cart[0] = new Book(123, 7.95f, "ky", "Sühne");
      cart[1] = new PrintedBook(124, 14.95f, "ky", "Leben");
      cart[2] = new EBook(125, 5.95f, "ky", "Schuld");
	  cart[3] = new CDAlbum(
	  "Forever", "Scorpions",15, 40, "Wooden Cover",13.87f,342 );
		printInvoice(cart);
   }
}