Java BoxProject using two classes -

im trying code print out new boxes based on original box class , im stuck. not sure variables need specify in grid class. nor know put in following class.

public void actionperformed(actionevent evt)  {     // maybe stuff here     repaint();    } 

here both of classes.

---the code has been updated since first reply---

box class

import java.awt.*;  public class box{    int upperleftx = 0;   int upperlefty = 0;   int height = 20;   int width = 20;   color color = color.red;    //constructor   public box(int i, int j, int k, int l, color m) {     upperleftx = i;     upperlefty = j;     height = k;     width = l;     color = m;   }    // paints box on screen   public void display(graphics g)   {     g.setcolor(color);     g.fillrect(upperleftx,upperlefty,width, height);   }    // getters , setters   public int getupperleftx() {     return upperleftx;   }    public void setupperleftx(int upperleftx) {     this.upperleftx = upperleftx;   }    public int getupperlefty() {     return upperlefty;   }    public void setupperlefty(int upperlefty) {     this.upperlefty = upperlefty;   }    public int getheight() {     return height;   }    public void setheight(int height) {     this.height = height;   }    public int getwidth() {     return width;   }    public void setwidth(int width) {     this.width = width;   }    public color getboxcolor() {     return color;   }    public void setboxcolor(color color) {     this.color = color;   }  } 

grid class

import java.applet.applet; import java.awt.*; import java.awt.event.actionevent; import java.awt.event.actionlistener;  public class grid extends applet implements actionlistener{   // declare variables here   public void actionperformed(actionevent evt)  {     // maybe stuff here     repaint();    }    public void paint(graphics g)   {        box box1 = new box(0,0,40,40,color.white);       box1.display(g);     // more stuff here     box box2 = new box(40,40,40,40,color.white);      box2.display(g);   }  } 

first of all, box should not extend applet. in fact, should not extend @ all. should serve storage container data boxes. not affect anything, confusing , doesn't make sense.

second, dan455 has pointed out, assignments in box constructor in wrong order. cause no harm, except parameters passed constructor mysteriously ignored, , seem every box constructed new box(0, 0, 20, 20).

third, actionlistener, don't need add unless have responds actionevent. if arrangement of boxes needs change, should have array of boxes drawn in paint, , if display of boxes needs updated, can modify array , call repaint, call paint possible.