java - Having trouble with JTable and JModel -

this clanmodel class. table based on tree map.

public class clanmodel extends abstracttablemodel{     private map<integer, clanmember> clanmembers;     private final string[] columnnames = {"name", "rank"};      clanmodel(map<integer, clanmember> clanmembers){         this.clanmembers = clanmembers;     }         @override     public int getrowcount() {         return clanmembers.size();     }      @override     public int getcolumncount() {         return 2;     }      @override     public string getcolumnname(int column){         return columnnames[column];      }      @override     public object getvalueat(int row, int column) {         if(column == 0) return clanmembers.get(row).getname();         if(column == 1) return clanmembers.get(row).getrank();         return 1;     }      @override     public void setvalueat(object value, int row, int column) {         if(column == 0) clanmembers.get(row).setname((string) value);         if(column == 1) clanmembers.get(row).setrank((rank) value);         firetablecellupdated(row, column);     } } 

this in gui constructor

clantable = new jtable(new clanmodel(clanmembers)); panel.add(clantable); 

the map filled on button press working. however, table doesn't appear before clicking button or after. error every time resize gui window.

i have rough idea of need fix hasn't been working out.

try moving setvisible() it's after add() , pack(). see initial threads.

public static void main(string[] args) {     eventqueue.invokelater(new runnable() {          @override         public void run() {             jframe f = new jframe();             f.setdefaultcloseoperation(jframe.exit_on_close);             jtable table = new jtable(new clanmodel(…));             f.add(new jscrollpane(table));             f.pack();             f.setlocationrelativeto(null);             f.setvisible(true);         }     }); }