Invoice.java

import javax.sound.sampled.Line;
import java.util.ArrayList;

public class Invoice {
    private Address billingAddress;
    private ArrayList<LineItem> items;
    public Invoice(Address anAddress)
    {
        items = new ArrayList<LineItem>();
        billingAddress = anAddress;
    }
    public void add(Product aProduct, int quantity)
    {
        LineItem anItem = new LineItem(aProduct, quantity);
        items.add(anItem);
    }

    public String format()
    {
String r = "                I N V O I C E \n\n"
        + billingAddress.format()
        +String.format("\n\n%-30s%8s%5s%8s\n", "Description", "Price", "Qty", "Total");
    for (LineItem item:items)
    {
        r=r+item.format() + "\n";
    }
    r = r + String.format("\n Amount due: $%8.2f", getAmountDue());
    return r;
    }
    public double getAmountDue()
    {
        double amountDue = 0;
        for (LineItem item : items)
        {
            amountDue = amountDue + item.getTotalPrice();
        }
        return amountDue;
    }



}