I want to give visual feedback to the user of the program while it's running but i can't get it to work.

When i try for example jLabel.setText("whatever"); it only updates after the whole program has completed (same for textFields).

The program is started from a jLabel that acts like a button inside a JFrame, and the jLabels i want to update are inside the same JFrame(it's an standalone app).

The processor level is at 48% while running so it's not that.
One more thing, if i minimize the program while it's running and i flip it to visual again while it's still running it remains black until the whole code has been executed completely and then turns back to normal viewing.

i would appreciate any help on the matter.