shop.java

AutoSale Interface

package autosale;

import java.io.*;
import java.util.*;

public class Shop {
    private final String fileName = "shop.dat";
    private List<Vehicle> vehicles;
    
    public Shop() {
        vehicles = new ArrayList<Vehicle>();
    }
    
    private static void printMenu() {
        System.out.println("\n\nMain menu:");
        System.out.println("1. New car");
        System.out.println("2. New motorcycle");
        System.out.println("3. Delete vehicle");
        System.out.println("4. Show all vehicles");
        System.out.println("5. Show all cars");
        System.out.println("6. Show all motorcycles");
        System.out.println("7. Quit");
    }
    
    private static int chooseOption(int min, int max) throws Exception {
        Scanner sc = new Scanner(System.in);
        
        while (true) {
            System.out.print("Enter a number: ");
            int option = sc.nextInt();

            if (option < min || option > max) {
                System.out.println("Invalid number, you must enter a value between " +
                        String.valueOf(min) + " and " + String.valueOf(max) + "!");
            } else {
                return option;
            }
        }
    }
    
    private void newCar() {
        vehicles.add(new Car());
    }
    
    private void newMc() {
        vehicles.add(new Motorcycle());
    }
    
    private void deleteVehicle() throws Exception {
        if (vehicles.size() == 0) {
            System.out.println("The shop is empty.");
            return;
        }
        
        showAllOfType(Vehicle.class);
        System.out.println("Select which vehicle to delete.");
        int selection = chooseOption(1, vehicles.size());
        int pos = selection - 1;
        
        vehicles.remove(pos);
    }
    
    private void showAllOfType(Class c) throws Exception {
        if (vehicles.size() == 0) {
            System.out.println("The shop empty.");
            return;
        }

        for (int i = 0 ; i < vehicles.size() ; i++) {
            if (c.isInstance(vehicles.get(i))) {
                System.out.println("");
                System.out.println(String.valueOf(i + 1));
                Printable p = vehicles.get(i);
                p.print();
                System.out.println(vehicles.get(i).getInsurancePrice());
            }
        }
    }
    
    private void load() throws Exception {
        File f = new File(fileName);
        if (!f.exists()) return;
        
        ObjectInputStream os = new ObjectInputStream(new FileInputStream(fileName));

        List v = (List)os.readObject();
        os.close();

        for (Object o : v) {
            vehicles.add((Vehicle)o);
        }
    }
    
    private void save() throws Exception {
        ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(fileName));

        os.writeObject(vehicles);

        os.close();
    }
    
    private void run() {
        //Vehicle v = new Vehicle();
        //vehicles.add(v);
        
        try {
            load();

            while (true) {
                printMenu();
                int choice = chooseOption(1, 7);

                switch (choice) {
                    case 1: //New car
                        newCar();
                        Collections.sort(vehicles, null);
                        break;
                    case 2: //New mc
                        newMc();
                        Collections.sort(vehicles, null);
                        break;
                    case 3: //Delete car
                        deleteVehicle();
                        break;
                    case 4: //Show all vehicles
                        showAllOfType(Vehicle.class);
                        break;
                    case 5: //Show all cars
                        showAllOfType(Car.class);
                        break;
                    case 6: //Show all mcs
                        showAllOfType(Motorcycle.class);
                        break;
                    case 7: //Quit
                        save();
                        System.exit(0);
                        break;
                }
            }
        } catch (Exception ex) {
            System.out.println("Unrecoverable error!");
            System.out.println(ex.getMessage());
            for (StackTraceElement ste : ex.getStackTrace()) {
                System.out.println(ste.getClassName() + 
                        "::" + ste.getMethodName() +
                        " Line:" + ste.getLineNumber());
            }
        }
    }
    
    public static void main(String[] args) {
        Shop s = new Shop();
        s.run();
    }
    
}