grocerycounter.java

A system to manage a grocery store with a single cash counter.

package grocerystore;

import java.util.*;

public class GroceryCounter implements Counter {

	private Map products = new HashMap();

	private List invoice = new LinkedList();
	private double netTotal;

	private String promoCode;
	private int promoDiscount;

	public void addProduct(String code, String desc, double price) {
		Product p = new Product(code, desc, price);
		products.put(code, p);
	}

	public void promo(String code, int discount) {
		promoCode = code;
		promoDiscount = discount;
	}

	public void read(String code, int pieces) throws NoSuchProduct{
		Product p = (Product) products.get(code);
		
		if (p == null)
			throw new NoSuchProduct();
		
		double price = pieces * p.getPrice();
		
		if (isPromo(p))
			price *= (100 - promoDiscount)/100.0;

		invoice.add(new Item(p, pieces, price));
		
		netTotal += price;
	}
	
	private boolean isPromo(Product p) {
		return p.getCode().equals(promoCode);
	}
	
	public double total() {
		return netTotal;
	}

	public double gross() {
		return netTotal / (1 + VAT);
	}

	public double taxes() {
		return netTotal / (1 + VAT) * VAT;
	}

	public void print() {
	
		Collections.sort(invoice);
		
		for(Iterator i=invoice.iterator(); i.hasNext(); ){
			Item item = (Item)i.next();
			
			System.out.print(item.getPieces()+ " x ");
			System.out.print("\t");
			System.out.print(item.getDesc());
			System.out.print("\t");
			System.out.println(item.getPrice());
		}
	}
	
	public void close() {
		invoice = new LinkedList();
		netTotal = 0;
	}
}