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Thread: Bug with an ArrayList

  1. #1
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    Question Bug with an ArrayList

    Hello, community!

    I've been working on a small app with a very simple algorithm. Said app must create 50 different objects with randomly generated atributtes (name, id and phone number must be random for each one of them) and store them in a Collection (ArrayList) which must be place in a .dat archive. A second app must retrieve the List and print it via console.

    First part seems to be well implemented, for each individual object can be printed. Override of the Object toString() is as follows:

    @Override
        public String toString(){
            String challenger = name+"\t\t"+id;
            return challenger;
        }

    The problem begins when trying to print the list, for the console prints only:

    // [Adrian 9109720 - Q] Whitneyener // when the print of the whole list is called via the System.out.println(list) or System.out.println(in.readObject()) command.

    Thanks in advance, for any small help is much appreciated!!

    public static void main(String[] args) throws FileNotFoundException, IOException, ClassNotFoundException {
     
            String name = "", id = "";
            int phone;
     
            ArrayList<Aspirante> list = new ArrayList<>();
     
            for (int i = 0; i < 50; ++i) {
                name = nameRandom();
                id = Integer.toString((int) (Math.random() * 10000000)) + " - " + capitalRandomChar();
                phone = (int) (Math.random() * 10000000);
                list.add(new Aspirante(name, id, phone, i));
            }
     
            try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream("lib\\list.dat"))) {
                out.writeObject(list);
                out.close();
            }
     
            try (ObjectInputStream in = new ObjectInputStream(new 
    FileInputStream("lib\\list.dat"))) {
                System.out.println(in.readObject());
                in.close();
            }
        }
    Last edited by salvadorInfor; December 30th, 2022 at 03:39 AM.

  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Bug with an ArrayList

    Can you make a small, simple, complete program that compiles, executes and shows the problem so we can see what is happening when it is executed for testing?
    If you don't understand my answer, don't ignore it, ask a question.

  3. #3
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    Default Re: Bug with an ArrayList

    Thanks a million Norm.

    As it turned out, writing a fresh, new code did result in a bugless execution. Sorry if I made you lose time. You do an incredible job here, keep up the good work!!

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