how to change jlabel text/color at runtime in swing aplicaiton

Question

I am working on project where I am doing three task on a button click which takes aprox. 2-3 mins I am changing jLabel's text using below code

lblStatus.setText( "Phase1 done successfully !!!, Phase2 started " );

but I get only "All phase done successfully !!!" text in jLabel after all run is completed.

Show us the code. Post an SSSCE. – user3164187 Oct 07 '16 at 11:24 — user3164187, Oct 07 '16 at 11:24

score 2 · Accepted Answer · edited May 23 '17 at 12:00

2

If you run your long running task in the EDT, the UI freezes until your task is done. Therefore you should do the long running task in a background thread. Within the background thread you can use SwingUtilties.invokeLater()to update the UI. Example:

SwingUtilities.invokeLater(new Runnable() {
  @Override
  public void run() {
    lblStatus.setText( "Phase1 done successfully !!!, Phase2 started " );
}});

For more information see SwingUtilities.invokeLater() why is it needed?

edited May 23 '17 at 12:00

Community

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answered Oct 07 '16 at 11:28

Stefan

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hi @Stefan Thank you, I was looking for alternative for thread but I think I won't chnage any think on UI at run time without Multi-threading – Rajesh Mhatre Oct 07 '16 at 11:52

Nicolas Filotto · Answer 2 · 2016-10-07T14:04:08.563

2

I believe that it is because your tasks will be executed by default by the Event Dispatch Thread which is responsible for managing all your Swing components as they are not thread-safe. This thread should only execute short tasks otherwise your application will become unresponsive. You should convert your tasks into a sub class of SwingWorker, then you will be able to use a PropertyChangeListener in order to modify the text of your status whenever the progress of your task evolves.

More details about Concurrency in Swing.

edited Oct 07 '16 at 14:04

answered Oct 07 '16 at 11:28

Nicolas Filotto

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Plus one for being the only correct answer submitted so far in this thread. – Andrew Thompson Oct 07 '16 at 13:59

score 0 · Answer 3 · answered Oct 07 '16 at 11:18

0

you can change the Color using this :

lblStatus.setForeground(Color.red);

and for changing text you can use setText() method , if you have problem with using that send all of the code here

answered Oct 07 '16 at 11:18

Mohsen_Fatemi

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score 0 · Answer 4 · answered Oct 07 '16 at 11:31

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to change color part text use html

lblStatus.setText("<html><b><font color='red'>Phase1 done successfully !!!</font></b>, Phase2 started");

answered Oct 07 '16 at 11:31

Piotr Rogowski

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how to change jlabel text/color at runtime in swing aplicaiton

4 Answers4