Reading a text file line by line and storing an object in the array

Question

The code I've currently created stores the first line of the text file, creates a new Vehicle object and puts it in the array at the first position of null, and stores the same line in every null value in the array. I need it to be able to:

Store the contents of the first line, then store a new Vehicle object in the first place in the array that is null. Then repeat until there are no more lines.

I believe it is a problem with my for loop. Note - I am required to use Array instead of ArrayList

public void addVehicle(Vehicle[] Honda) throws FileNotFoundException
{

        if(canAddVehicle() == true)
        {
        for(int i = 0; i < vehicles.length; i++)
        {
            if(vehicles[i] == null)
            {
                Scanner reader = new Scanner(file);

                Honda[i] = new Vehicle();
                Honda[i].readRecord(reader);
                vehicles[i] = Honda[i];

                reader.close();
            }
        }
            System.out.println("Vehicle Added!");
        }
        else
        {
            System.out.println("You can not add more than 4 vehicles.");
        }
}

Vehicle class:

public void readRecord(Scanner reader)
{

    setMake(reader.next());
    setModel(reader.next());
    setYear(reader.nextInt());
    setvin(reader.next());
    setValue(reader.nextDouble());
    setMilesDriven(reader.nextInt());
    setLastOilChange(reader.nextInt());



}

Data file:

Hyundai Sonata  2010    ABC236347NM2N2NW2   18455.34    8765    7567
Chevy   Blazer  1998    1234H32343LMN3423   29556.65    38559   38559

//EDIT\\ Constraits : I cannot create any new public methods or constructors, and I cannot have any additional class level data

Answer 1

You're looping within the readRecord method, even though that's meant to only store one object, isn't it?

It's possible that you can just remove the while loop - although that then relies on the addVehicle caller knowing how many entries are in the file.

It seems more likely that you should have a method to read everything from a file, populating a List<Vehicle> and returning it. For example:

public List<Vehicle> readVehicles(String file)
{
    Scanner reader = new Scanner(file);

    List<Vehicle> vehicles = new ArrayList<Vehicle>();
    try
    {
        while (reader.hasNextLine())
        {
            vehicles.add(Vehicle.readFromScanner(reader));
        } 
    }
    finally
    {
        reader.close();
    }
    return vehicles;
}

// In vehicle
public static Vehicle readFromScanner(Scanner scanner)
{
    String make = reader.next();
    String model = reader.next();
    int year = reader.nextInt();
    String vin = reader.next();
    // Don't use double for currency values
    BigDecimal value = reader.nextBigDecimal();
    int milesDriven = reader.nextInt();
    // Shouldn't this be some sort of date type?
    int lastOilChange = reader.nextInt();

    // I'll assume you have a constructor like this
    return new Vehicle(make, model, year, vin, value, milesDriven,
                       lastOilChange);
}

Answer 2

Found my solution!

public boolean addVehicle(Vehicle[] Honda) throws FileNotFoundException
{
    boolean found = false;
    int position = 0;
        if(canAddVehicle() == true)
        {
            for(int i = 0; i < vehicles.length && !found; i++)
            {
                if(vehicles[i] == null)
                {
                    position = i;
                    found = true;
                }
            }

               Scanner reader = new Scanner(file);
               while(reader.hasNext())
               {
                   Honda[position] = new Vehicle();
                   Honda[position].readRecord(reader);
                   vehicles[position] = Honda[position];
                   position++;

               }
                reader.close();
                return true;
        }
        return false;
}