The elements change only after another action

[juvenalb]

tf.username.setEnabled(false);
tf.password.setEnabled(false);
tf.cb.setEnabled(false);
tf.button.setEnabled(false);
tf.imageLabel.setVisible(true);

Parser pars=new Parser(user, password);
String[] answer=pars.getData();

tf - That's it. JPanel♪ ♪ Parser departures GET and POST by request Apache HtpClient and then work. Excel ♪ Apache Poi♪

The problem is that the change on board occurs only after the end of the method getData()♪

[Alberto]

Problem is, you've got performance. getData() It's in the same flow as the GUI's. Put it in a separate flow and it's gonna be okay, read the offs for a more detailed understanding. https://docs.oracle.com/javase/tutorial/uiswing/concurrency/ and special attention https://docs.oracle.com/javase/tutorial/uiswing/concurrency/dispatch.html

I mean, in your case there must be something like that:

tf.username.setEnabled(false);
tf.password.setEnabled(false);
tf.cb.setEnabled(false);
tf.button.setEnabled(false);
tf.imageLabel.setVisible(true);
new Thread(new Runnable() {

@Override

public void run() {

Parser pars=new Parser(user, password);

String[] answer=pars.getData();

// Все остальные действия с результатом

}

}).start();