not able to show data in a jTextField

Question

I am writing a socket programming. It has GUI for server and client. In the server GUI there is a textfield which shows the word requested by user. But I am having problem in showing the word.

I have tried

txtWord.setText(sentword);

It is not showing the word in the textfield. But when I write this

txtWord.setText(sentword);
JOptionPane.showMessageDialog(null, "the requesed word is: "+sentword);

then it shows the word in textfield and also shows it in the messagebox.

I have tried repaint() but it dint work. Please suggest me some solution as soon as possible

Answer 1

as @Binyamin Sharet correctly commented, you have a Concurrency in Swing issue.

• your Swing GUI doesn't care about long and hard tasks you're running in the background

• even JTextField#setText() is declared as thread safe, output from Socket (i.e.) by default never notified Event Dispatch Thread

• correct way could be to use a SwingWorker that has been created specifically to run long and hard tasks background to the Swing GUI and output to the GUI on event thread or EDT

• or even easier is to use a Runnable in a Thread but making sure that all output to the Swing GUI is queued on the Swing event thread by placing it in a Runnable and calling it with invokeLater()

• A dirty hack is to wrap code lines like so:

txtWord.setText(sentword);
JOptionPane.showMessageDialog(null, "the requesed word is: "+sentword);

into invokeLater(), but in this case your GUI will be unresponsive to Mouse or Keyboard events until Socket (in your case) ended