Question

In my program there are 4 threads that addElemets to a model of a jlist at the same time. This causes jlist to blink, throw excpetions or even crash, because of the too many updates or repaints.

I tried to put some delay that fixed my problem but I was losing to much precious time.

What can I do?

this code simulates my problem:

new Thread(new Runnable() {
    @Override
    public void run() {
        for(int i=0; i<4; i++){
            new Thread(new Runnable() {
                @Override
                public void run() {
                    for(int o=0; o<2000; o++){
                        model.addElement("add");
                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException ex) {
                            Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
                        }
                    }
                }
            }).start();
        }
   }
}).start();

Answer 1

The model.addElement(“add”); should be something like this:

SwingUtilities.invokeLater(new Runnable() {
    public void run() {
        listModel.addElement("add");
    }
});

This way you make sure that the elements are added under the EDT and not in some random thread.