java - repaint function not work when event happen -

i trying change button background color 10 time when event happen?

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private void jbutton2actionperformed(java.awt.event.actionevent evt) {                                              try {         (int = 0; < 10; ++i) {             random r = new random();             jbutton2.setbackground(new color(r.nextint(150), r.nextint(150), r.nextint(150)));             jbutton2.repaint();             thread.sleep(200);         }     } catch (exception e) {         system.out.println(e.tostring());     }  } 

but button show last color??

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thanks it's work correctly

int x = 0; timer timer; private void jbutton2actionperformed(java.awt.event.actionevent evt) {                                               timer = new timer(1000, new actionlistener() {         @override         public void actionperformed(actionevent e) {             random r = new random();             jbutton2.setbackground(new color(r.nextint(150), r.nextint(150), r.nextint(150)));             jbutton2.repaint();             if(x==10){                 timer.stop();                 x=0;             } else{                 x++;             }         }     });     timer.start(); }    

don't call thread.sleep(...) on swing event thread puts entire swing gui sleep. in other words, gui no painting, accepts no user input or interaction @ , becomes useless while event (also known event dispatch thread or edt). use swing timer instead. please check out swing timer tutorial more on this.

also have @ of answers this question, including mkorbel's.