java - Refreshing/updating JTable with setValueAt doesn't work correctly -

i'm working on project college , need 2 of jframe. first 1 main menu , second 1 visible when jbutton(run) pressed. need paint memory in both of jframe, used jtable show memory.

memory class is:

    public class memory extends jpanel{      private jpanel panel;     private jtable table;     private string[] array;      private jscrollpane scrollpane;      public memory()     {        array = new string[256]        this.addmemorygui();     }      public final jpanel addmemorygui()     {         this.panel = new jpanel();         this.panel.setpreferredsize(new dimension(315,490));         this.panel.setlayout(null);         this.add(panel);          string info[][] = new string[256][2];         for(int j=0;j<256;j++)         {             info[j][0] = j;              info[j][1] = null;         }         string[] title = new string[]{"address","value"};          defaulttablemodel model = new defaulttablemodel(info,title);         table = new jtable(model){         @override         public boolean iscelleditable(int rowindex, int colindex) {         return false;            }         };         defaulttablecellrenderer centerrenderer = new defaulttablecellrenderer();         centerrenderer.sethorizontalalignment( jlabel.center );         table.getcolumnmodel().getcolumn(0).setcellrenderer( centerrenderer );         table.getcolumnmodel().getcolumn(1).setcellrenderer( centerrenderer );         jtableheader header = table.gettableheader();         header.setbackground(color.gray);         this.scrollpane = new jscrollpane(this.table);         this.scrollpane.setbounds(0, 0,315, 490);         this.panel.add(this.scrollpane);         return panel;     }      public void setaddrvalue(int addr,string value)     {         memory.this.array[addr] = value;         this.table.setvalueat(value,addr , 1);     }      public string getaddrvalue(int addr)     {         return memory.this.array[addr];     }      public string[] getmemory()     {         return memory.this.array;     }        public void deletevalue(int i)     {         array[i]=null;         this.table.setvalueat(null, i, 1);     } } 

i add jtable main jframe , jcomponents:

public class maingui extends jframe{   private jtextfield field1;     private jtextfield field2; private jbutton button1;     private jbutton button2; private memory mem;  public maingui()     {         this.graphiccomponents();       }   public final void graphiccomponents()     {         this.settitle("machine");         this.setsize(800, 620);         this.setlayout(null);         this.setdefaultcloseoperation(jframe.exit_on_close);          this.setresizable(false);          this.field1=new jtextfield();         this.field1.setbounds(10,50,70,20);         this.add(field1);          this.field2=new jtextfield();         this.field2.setbounds(90,50,70,20);         this.add(field2);          this.button1=new jbutton("write value");         this.button1.setbounds(170,50,130,20);         this.button1.addactionlistener(new actionlistener() {           @override          public void actionperformed(actionevent e)          {                        maingui.this.mem.setaddrvalue(maingui.this.field1.gettext().tostring(),maingui.this.field2.gettext().tostring() );          }          });         this.add(button1);          this.button2 = new jbutton("run");         this.button2.setbounds(500,550,100,30);         this.button2.addactionlistener(new actionlistener() {           @override          public void actionperformed(actionevent e)          {                        executiongui exe = new executiongui(mem);                       exe.setvisible(true);          }          });         this.add(button2);          this.mem = new memory();         this.mem.setbounds(450, 30, 315, 490);         this.add(mem); 

} }

here in code, setvalueat() method work perfect , there no problem. when use same code of jtabel in second jframe when press run jbutton create new jtable not in memory class , insert value jtable using setvalueat(), jtabel doesn't update.

code of second jframe:

public class executiongui extends jframe {   private jtextfield field1;         private jtextfield field2;     private jbutton button1; private jscrollpane scrollpane;         private jbutton button2;     private memory mem; private jtable table; private static defaulttablemodel model; private string info[][];     private string[] title; private memory mem;   public executiongui(memory mem)     {         this.mem = mem;          this.graphiccomponents();     }   public final void graphiccomponents()     {        this.settitle("run");         this.setbounds(200, 100, 800, 600);         this.setlayout(null);         this.setdefaultcloseoperation(jframe.exit_on_close);          this.setresizable(false);           this.info = new string[256][2];         for(int j=0;j<256;j++)         {             info[j][0] = j;             if(mem.getaddrvalue(j)==null)             {              }             else             {                 info[j][1] = mem.getaddrvalue(j);             }         }         title = new string[]{"address","value"};          model = new defaulttablemodel(info,title);         table = new jtable(model){         @override         public boolean iscelleditable(int rowindex, int colindex) {         return false;            }         };         defaulttablecellrenderer centerrenderer = new defaulttablecellrenderer();         centerrenderer.sethorizontalalignment( jlabel.center );         table1.getcolumnmodel().getcolumn(0).setcellrenderer( centerrenderer );         table1.getcolumnmodel().getcolumn(1).setcellrenderer( centerrenderer );         jtableheader header = table.gettableheader();         header.setbackground(color.gray);         this.scrollpane = new jscrollpane(table);         this.scrollpane.setbounds(610, 30,170, 470);         this.add(this.scrollpane);          this.field1=new jtextfield();         this.field1.setbounds(10,50,70,20);         this.add(field1);          this.field2=new jtextfield();         this.field2.setbounds(90,50,70,20);         this.add(field2);          this.button1=new jbutton("write value");         this.button1.setbounds(170,50,130,20);         this.button1.addactionlistener(new actionlistener() {           @override          public void actionperformed(actionevent e)          {                        table.setvalueat(maingui.this.field2.gettext().tostring(),maingui.this.field1.gettext().tostring(),1 );          }          });         this.add(button1);     } 

so have problem second jframe , can't refresh jtable new data. have tried more 1 way take right result there nothing.

thanks help.