Check out example codes for "jtable and combo box swing java". It will help you in understanding the concepts better.

Code Example 1

{
TableColumnModel cm = myTable.getColumnModel();
  cm.getColumn(0).setResizable(false);
  cm.getColumn(0).setPreferredWidth(45);
  cm.getColumn(1).setResizable(false);
  cm.getColumn(1).setPreferredWidth(45);
  cm.getColumn(2).setResizable(false);
  cm.getColumn(2).setPreferredWidth(45);
  cm.getColumn(6).setPreferredWidth(55);
  cm.getColumn(7).setPreferredWidth(55);
  cm.getColumn(12).setCellEditor(new DefaultCellEditor(
    new JComboBox(new DefaultComboBoxModel(new String[] {
      "Yes",
      "No",
      "Maybe"
    }))));
}

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