java - JProgressBar.setMaximum(int) sometimes doesn't seems to work -

i have jprogressbar need set new minimum, maximum , progress value each time task of queue done, using code below:

this.progressbar.setminimum(minimum); this.progressbar.setmaximum(maximum); this.progressbar.setvalue(progress); 

but, noticed sometimes, setmaximum(int) method doesn't seems work, because progress bar still working old maximum value.

then wrote test code , ran it:

progressbar.setmaximum(10); system.out.println(progressbar.getmaximum()); 

sometimes prints 10 expected, , prints old value: different 10.

i spent hours on google , javadocs, tried call revalidate() , repaint() on jprogressbar's parent, , nothing. tried call thread.sleep(10) wait awt threads run tasks , didn't work.

any ideas?

edit: provided more code:

/* applet construct view , init thread. */ public class fastapplet extends applet {     private jprogressbar progressbar;     private jpanel panel;     private runnable runnable;      @override     public void init() {         try {             java.awt.eventqueue.invokeandwait(new runnable() {                 @override                 public void run() {                     createandshowgui();                     initthreads();                 }             }         } catch (exception e) {             e.printstacktrace();         }     }      private void createandshowgui() {         panel = new jpanel();         progressbar = new jprogressbar();         progressbar.setstringpainted(true);         panel.add(progressbar);     }      private void initthreads() {                 runnable = new myrunnable(progressbar);              thread thread = new thread(runnable);         thread.start();     } }  /* runnable update progress , call setmaximum(int) on jprogressbar */ public class myrunnable {     private int progress;     private final jprogressbar progressbar;      myrunnable(jprogressbar progressbar) {         this.progressbar = progressbar;     }      @override     public void run() {         // tasks , update progressbar using progressbar.setvalue(progress)         // when done, reset progress bar new maximum:         definenewprogressbar(0, 0, newmaximum);     }      public void definenewprogressbar(int progress, int minimum, int maximum) {         this.progress = progress;          component component = progressbar.getparent();         jpanel panel = (jpanel) component;          this.progressbar.setminimum(minimum);         this.progressbar.setmaximum(maximum);         this.progressbar.setvalue(progress);          panel.revalidate();         panel.repaint();     } } 

you wrote in comments call setmaximum() not edt. should call edt this:

swingutilities.invokelater(new runnable() {     @override     public void run() {         progressbar.setmaximum(10);     } }); 

if use java8, can using lambda expression:

swingutilities.invokelater(()->progressbar.setmaximum(10));