java - won't repaint a different Month after pressing button in my calendar -

i'm trying build calendar in java little project thought of, can't seem change name of month every time click next button. here's code!

package drawing;  import javax.swing.*;  import java.awt.*; import java.awt.event.*; public class drawing_something extends jpanel{     int[] calender_squares = {1, 2, 3, 4, 5, 6, 7};     string[] month = {"january", "february", "march", "april","may","june","july",             "august","september","october","november","december"};     int = 0;     graphics c;     @override     public void paintcomponent(graphics c){         super.paintcomponent(c);         this.setbackground(color.white);         int width = 55, height = 65;          (int in: calender_squares) {             (int counter = 0; counter < 7; counter++){                 c.drawrect(50, 50, 100, 100);                 c.drawrect(50, 50, 700, 500);                 c.copyarea(50, 50, 600, 500, 100, 0);                 c.copyarea(50, 50, 600, 400, 0, 100);             }         }          (int date = 1; date <= 30; date++) {             string s = string.valueof(date);             c.drawstring(s, width, height);             if (date <= 6){                 width += 100;             } else if (date == 7){                 width = 55;                 height = 165;             }else if (date <= 13){                 width += 100;             }else if (date == 14){                 width = 55;                 height = 265;             }else if (date <= 20){                 width += 100;             }else if (date == 21){                 width = 55;                 height = 365;             }else if (date <= 27){                 width += 100;             }else if (date == 28){                 width = 55;                 height = 465;             }else if (date <= 30){                 width += 100;             }         }         c.setfont(new font("default", font.bold, 40));         c.drawstring(month[i], 320, 45);     }      public drawing_something(){         setlayout(new borderlayout());         jbutton n = new jbutton("next");         jbutton b = new jbutton("back");         jpanel p = new jpanel();          p.add(b);         p.add(n);          add(p, borderlayout.south);          b.addactionlistener(new handlerclass());         n.addactionlistener(new nextclass());     }     public class handlerclass implements actionlistener{         public void actionperformed(actionevent e){         }     }     public class nextclass implements actionlistener{         public void actionperformed(actionevent e){             if (i == 11){                 = 0;             }             = + 1;             c.drawstring(month[i], 320, 45);         }     }      public static void main(string[] args){         jframe mainframe = new jframe("calender");         mainframe.add(new drawing_something());         mainframe.setsize(850, 650);         mainframe.setdefaultcloseoperation(jframe.exit_on_close);         mainframe.setvisible(true);     } } 

if appreciated!!

thanks in advance!!

don't maintain reference graphics context used paint component, not how custom painting done.

instead, once update i value, call repaint

you shouldn't adding components draw_something component, these cover been painted.

instead, add components separate container , use setters , getters change state of calendar pane