Temporary exam answer for the burger joint simulator

burgersimulator.java

public class Simulation {
    public static void Main(String[] args) {
        Monitor mon = new Monitor();
        ArrayList<Chef> chefs         = new ArrayList<Chef>();
        ArrayList<Customer> customers = new ArrayList<Customer>();
        ArrayList<Seller> sellers     = new ArrayList<Seller>();
        Customers simulator = new Customers();
        Statistics statistics = new Statistics();

        for(int i = 0; i < 7; i++) {
            chefs.add(new Chef());
            chefs[i].start();
        }

        for (int i = 0; i < 3; i++) {
            sellers.add(new Seller());
            sellers[i].start();
        }

        simulator.start();
        statistics.start();
    }
}

public class Monitor {
    private LinkedList<Integer> customers;
    private LinkedList<Integer> orders;
    private LinkedList<Integer>[] shelfs;
    private int[] inProgress;
    private int thrownBurgers;
    private int missedDeadlines;
    private int orderedBurgers;

    public Monitor() {
        shelfs = new LinkedList<Integer>[Util.shelfs()];
        customers = new LinkedList<Integer>(); // requested orders?
        orders = new LinkedList<Integer>();    // order
    }

    // Simulate a chef manufacturing a burger
    public synchronized void manufactureBurger() {

    }

    // Simulate a seller handling an order
    public synchronized void handleOrder() {
        // 1. Wait for new customer
        try {
            while (customers.size() == orders.size()) {
                wait();
            }
        } catch (InterruptedException e) {
            return;
        }

        // 2. Place order in chefs
        orders.addLast(customers.getLast());
        orderedBurgers++;

        // 3. While waiting for chefs to prepare burgers, throw old ones
        int currentTime = Util.currentTime();
        int waitLength = currentTime + Util.manufacturingTime(customers.getLast());
        while (waitLength - currentTime >= 0) {

        }

    }

    // Placing a new customer in queue
    public synchronized void newCustomer(int burgerType) {
        customers.add(burgerType);

        notifyAll();
    }

    // Return a vector containing {thrownBurgers,missedDeadlines,orderedBurgers}
    public synchronized int[] gatherStatistics() {
        int[] stats                   = new int[3];
        stats[0]                      = thrownBurgers;
        stats[1]                      = missedDeadlines;
        stats[2]                      = orderedBurgers;

        thrownBurgers                 = 0;
        missedDeadlines               = 0;
        orderedBurgers                = 0;

        return stats;
    }
}

public class Customer extends Thread {
    //LinkedList<Integer> customers;
    Monitor mon;
    public Customer(Monitor mon) {
        this.mon = mon;
        //customers = new LinkedList<Integer>();
    }

    public void run() {
        while(!isInterrupted) {
            int type = Util.newCustomer();
            //customers.add(type);
            mon.newCustomer(type);
        }
    }
}

public class Seller extends Thread {
    Monitor mon;
    public Seller(Monitor mon) {
        this.mon = mon;
    }

    public void run() {
        while(!isInterrupted) {
            mon.handleOrder();
        }
    }
}

public class Chef extends Thread {
    Monitor mon;
    public Chef(Monitor mon) {
        this.mon = mon;
    }

    public void run() {
        while(!isInterrupted) {
            mon.manufactureBurger();
        }
    }
}

public class Statistics extends Thread {
    Monitor mon;
    public Statistics(Monitor mon) {
        this.mon = mon;
    }

    public void run() {
        while(!isInterrupted) {
            int[] stats = mon.gatherStatistics();
            synchronized(stats) {
                System.out.println("Thrown burgers:   " + stats[0].toString());
                System.out.println("Missed deadlines: " + stats[1].toString());
                System.out.println("Ordered burgers:  " + stats[2].toString());
                System.out.println("");
            }
        }
    }
}