CODEWITHSUNDEEP
javaiobinaryfiles
user2745043
user2745043

Reputation: 199

Read arbitrary number of objects from a binary file

Ok so I have an 'Animal' class that is abstract with subclasses 'Dog' and 'Bird' I need to write a program to read and unknown number of Animal objects from a binary file.

public static void main(String[] args) throws FileNotFoundException {
    readAnimals("birdsAndDogs.dat");

}

public static List<Animal> readAnimals(String filename) {
    List<Animal> animals = new ArrayList<Animal>();
    ObjectInputStream ois = null;
    try {
        ois = new ObjectInputStream(new FileInputStream(filename));

        try {
            while (true) {
                Animal a =(Animal) ois.readObject();

                if (a instanceof Animal)
                    animals.add((Animal)a);
                System.out.println(a);
            }
        }
        catch (EOFException eof) {
            ois.close();
            ois = null;
            return animals;
        }
    }
    catch (Exception e) {
        return null;
    }
}   
}

This is my first time trying to read binary files, so take it easy, the code may be pretty messy I'm not sure but my main problem is I keep getting a FileNotFoundExeption, but the file is in the same package and location, any ideas?

also is the code it self structured correctly?

Thanks for any and all help

Upvotes: 0

Views: 257

Answers (1)

Sotirios Delimanolis
Sotirios Delimanolis

Reputation: 280138

When the application sees

new FileInputStream("justADog.dat")

it looks for the file name in the directory the application was launched from. I very much doubt your application was ran from the package your class is in.

Either provide a full path to the file or move the file to the location your application is ran from. With Eclipse, the application is started from your project folder.

Upvotes: 1

Related Questions