java - JFrame update when data change -

how update jframe display when data in program changes?

a bit of context. i'm working on sort of ant colony simulation (it's not school project. well... not school ;p (i'm not helping either, i'm doing fun))

in simulation, try display map of current state of simulation, displaying position of food, ant, colony, rocks...

what i'm doing currently: have "two maps". each 2d array. first 1 contain id of each element, other 1 contain icon (at right position of array/map) shown user, , display important object of case (for example, if ant on same square colony, colony show up).

the data behind each map work fine , contain want.

the problem that, once simulation start running, frame still stuck on cycle 0.

so (for 1 didn't read above), how can update frame display when map data changed?

some bits of current code: edit: compilable version cheap way make value change periodically

my "main"

public class finit {     public static string[][] textgrid=              {{"+", "-", "-", "-", "-", "-", "+"},              {"|", " ", " ", " ", " ", "#", "|"},              {"|", " ", " ", " ", " ", " ", "|"},              {"|", " ", " ", " ", "o", " ", "|"},              {"|", " ", " ", " ", " ", " ", "|"},              {"|", " ", "#", "o", "©", "o", "|"},              {"+", "-", "-", "-", "-", "-", "+"}};     public static void main(string[] args) throws interruptedexception{         ffenetre fenetre = new ffenetre();         fenetre.fmapwindows(textgrid.length, textgrid[0].length);         while(true){             fenetre.repaint();             thread.sleep(500);             if(textgrid[5][4].equals("©")) textgrid[5][4]=" ";             else textgrid[5][4]="©";         }     } } 

the other relevant bit:

public class ffenetre extends jpanel {       public ffenetre test;      public void fmapwindows(int x, int y){         jframe frame = new jframe("carte");         frame.setdefaultcloseoperation(jframe.exit_on_close);         frame.setsize((x+1)*20, (y+2)*20+5);         frame.setlocationrelativeto(null);         ffenetre test = new ffenetre();         frame.add(test);         frame.setvisible(true);         //frame.setcontentpane(new fgraphiquemapicones());     }      @override     public void paintcomponent(graphics g){         super.paintcomponent(g);         font font = new font("monospaced", font.plain, 20);         g.setfont(font);         for(int a=0; a<finit.textgrid.length; a++){             for(int b=0; b<finit.textgrid[0].length; b++){                 g.drawstring(finit.textgrid[b][a], (a)*20+5, (b+1)*20);             }         }     } } 

i don't know doing after @override part, tried implement solutions of different people, none made handle wanted (not button nor mouse movement)