import java.util.ArrayList;
import java.util.Vector;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class Main {
public static void main(String[] argv) throws Exception {
DefaultTableModel model = new DefaultTableModel();
JTable table = new JTable(model);
model.addColumn("Col1");
model.addRow(new Object[] { "r1" });
model.addRow(new Object[] { "r2" });
model.addRow(new Object[] { "r3" });
Vector data = model.getDataVector();
Vector row = (Vector) data.elementAt(1);
// Overwrite the first row with the copy
Vector firstRow = (Vector) data.elementAt(0);
for (int i = 0; i < row.size(); i++) {
firstRow.set(i, row.get(i));
}
JFrame f = new JFrame();
f.setSize(300, 300);
f.add(new JScrollPane(table));
f.setVisible(true);
}
}