1 — use a DefaultTableModel in your table and then call
setRowCount in the model:
((DefaultTableModel)table.getModel()).setRowCount(yourCount);
2 —
DefaultTableCellRenderer renderer =
(DefaultTableCellRenderer)table.getDefaultRenderer(String.class);
renderer.setHorizontalAlignment(JLabel.CENTER);
3 —
textArea.setLineWrap(true);
textArea.setWrapStyleWord(true);
4 — I have never had trouble with ButtonGroup in j2se 1.5
How are you using it to conclude that it is "not working?"
See
Lesson: Using Swing Components for more.