public String toString() {

        String title = "*************************"+newLine;
        title += "* Garage OpenClassrooms *"+newLine;
        title += "*************************"+newLine;

        String str = title;

        try {
            ois = new ObjectInputStream(
                new BufferedInputStream(
                    new FileInputStream(
                        new File("voitures.txt"))));

            try {
                str += ois.readObject().toString()+newLine;
                str += ois.readObject().toString()+newLine;
                str += ois.readObject().toString()+newLine;
                str += ois.readObject().toString()+newLine;
                str += ois.readObject().toString()+newLine;
            }catch(ClassNotFoundException e) {
                e.printStackTrace();
            }

            ois.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return str;
    }