Swing window doesn't appear after getting input from Console

Question

I have a simple swing window in order to load files.

This appear in the class analyzedLoad, in a function analyzedloads()

JFileChooser fc = new JFileChooser();
JFrame frame = new JFrame();
int returnVal = fc.showOpenDialog(frame);
frame.dispose();
if (returnVal == JFileChooser.APPROVE_OPTION) {

Where I apply the function without get an input from the user, all fine. But where I get an input from the user, in this way:

    int al= 0;
     Scanner in = new Scanner(System.in);
       System.out.println("for choose file, press 1; for save, press 2");
       al= in.nextInt();
       if (al== 1){
        analyzedLoad.analyzedloads(); // A static function which open the swing window

The window doesn't appear, and the process continue to run, without doing anything.

Thanks.

too few code, too few words, for better help soonee please edit your question with [SSCCE](http://sscce.org/) — mKorbel, Feb 28 '12 at 08:06
and removing `al= in.nextInt(); if (al== 1){` makes window open again? — Oleg Mikheev, Feb 28 '12 at 08:53
@Qwe: Yes, If I remove the part of getting an input from a console, Its work fine. — Adam Sh, Feb 28 '12 at 09:00
and if you add `System.out.println("I'm here");` as the first line in `analyzedloads()` it will be printed? — Oleg Mikheev, Feb 28 '12 at 09:09

score 2 · Accepted Answer · answered Feb 28 '12 at 11:16

2

Becaue "a scanning operation may block waiting for input," I suspect you're blocking the event dispatch thread. Instead use a File Chooser to obtain a file reference.

answered Feb 28 '12 at 11:16

trashgod

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score 1 · Answer 2 · answered Feb 28 '12 at 08:05

1

Try adding a second mywindow.setVisible(true) after the console operation.

answered Feb 28 '12 at 08:05

ApprenticeHacker

21,351
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@It doesn't help. I add it to the class analyzedLoad, where my windows is known, and the problem continue. – Adam Sh Feb 28 '12 at 08:15

score 1 · Answer 3 · answered Feb 28 '12 at 08:17

1

You might want to try to declaring the analyzeLoad variable as final and do something like so:

SwingUtilities.invokeLater(new Runnable()
{
    @Override
    public void run()
    {
         analyzedLoad.analyzedloads();
    }
}

or since the method is static:

    SwingUtilities.invokeLater(new Runnable()
    {
        @Override
        public void run()
        {
             YourClass.analyzedloads();
        }
    }

That being said, without more code we can only speculate.

answered Feb 28 '12 at 08:17

npinti

51,780
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It doesn't help. Can you tell me plz which more code I need to give? I wrote the relevant part in the two classes. Thanks – Adam Sh Feb 28 '12 at 08:35
@AdamSh: Whenever messing around with GUI it is usually good to make a distinction between showing nothing and doing nothing. Did you try to initialize the JFrame to something that is actually visible, maybe the `JFrame` is being opened but it is not visible. I would recommend you first create a visible `JFrame` and then try to load a `JFileChooser` – npinti Feb 28 '12 at 08:41
Without the input from the console, everything works fine: The window appear, and the program work well. So I guess that my GUI's defenition is fine. Also, I add fc.setVisible(true); after the define of fc, and It didn't help as well. – Adam Sh Feb 28 '12 at 08:54
@AdamSh: The only thing that comes to mind is that the `Scanner` might be hanging your program. Can you try to do a `in.close()` after you get the value from `in.nextInt()`. – npinti Feb 28 '12 at 08:57
@AdamSh: Would it be possible to replace the console section with a radio group and a button? – npinti Feb 28 '12 at 09:07

Swing window doesn't appear after getting input from Console

3 Answers3