Update JTable

Question

Hello,
I always thought that the table takes care for the view, whereas the tablemodel handles the data. But how come that an update with tblModel.setDataVector(...) destroys (resets to default) the preferred column width? Rather how can this be avoided?
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
public class UpdateTable
{ static String headers[]= {"Baum", "Blatt", "Frucht","H�usigkeit"};;
  static String data[][]= {
     {"Eiche", "gez�hnt","Eichel","ein"},
     {"Buche", "glatt", "Buchecker","ein"},
     {"Tanne", "Nadel", "Zapfen","ein"},
     {"Pappel", "wechselst�ndig","Kapsel","zwei"},
  static DefaultTableModel tblModel;
  public UpdateTable()
  { JFrame frame = new JFrame("UpdateTable");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container contentPane = frame.getContentPane();
    tblModel = new DefaultTableModel(data, headers)
    { // Make read-only
      public boolean isCellEditable(int x, int y)
      { return false;
    final JTable table = new JTable(tblModel);
    table.getColumnModel().getColumn(1).setPreferredWidth(200);
    table.getColumnModel().getColumn(3).setPreferredWidth(20);
      // Set selection to first row
    ListSelectionModel selectionModel = table.getSelectionModel();
    selectionModel.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    selectionModel.addListSelectionListener (new ListSelectionListener()
    { public void valueChanged(javax.swing.event.ListSelectionEvent e)
      { if (e.getValueIsAdjusting()) return;
            System.out.println(table.getSelectedRow());
      // Add to screen so scrollable
    JScrollPane scrollPane = new JScrollPane (table);
    contentPane.add(scrollPane, BorderLayout.CENTER);
    frame.setSize(500, 100);
    frame.setVisible(true);
  public static void main(String args[])
  { new UpdateTable();
    try
    { Thread.sleep(3000);
    catch (InterruptedException e)
    { System.out.println ("Fehler: "+ e.toString());
    String headers_neu[] = {"Arbre", "Feuille", "Fruit", "Maisonette"};
//  Even if the next line is taken out the width changes.
    headers = headers_neu;
    tblModel.setDataVector((Object[][])data, (Object[])headers);
}Bye
J�rg

Answer 1

I agree, it doesn't make sense. Why does a setDataVector() method need a data vector and a column vector. Anyway I extended the DefaultTableModel and added a refreshDataVector() method that only needs a data vector.
import java.awt.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class RefreshTableModel extends DefaultTableModel
    public RefreshTableModel()
        super();
    public RefreshTableModel(int numRows, int numColumns)
        super(numRows, numColumns);
    public RefreshTableModel(Object[][] data, Object[] columnNames)
        super(data, columnNames);
    public RefreshTableModel(Object[] columnNames, int numRows)
        super(columnNames, numRows);
    public RefreshTableModel(Vector columnNames, int numRows)
        super(columnNames, numRows);
    public RefreshTableModel(Vector data, Vector columnNames)
        super(data, columnNames);
    public void refreshDataVector(Vector data)
        fireTableRowsDeleted(0, getRowCount() - 1);
        dataVector = data;
        fireTableRowsInserted(0, getRowCount() - 1);
    public void refreshDataVector(Object[][] data)
        refreshDataVector( convertToVector(data) );
    public static void main(String[] args)
        Object[][] data = { {"four", "A"}, {"three", "B"}, {"two", "C"}, {"one", "D"} };
        String[] columnNames = {"Number", "Letter"};
        RefreshTableModel model = new RefreshTableModel(data, columnNames);
        JTable table = new JTable(model);
        table.getColumnModel().getColumn(0).setPreferredWidth(100);
        table.getColumnModel().getColumn(1).setPreferredWidth(200);
        JScrollPane scrollPane = new JScrollPane( table );
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.getContentPane().add( scrollPane );
        frame.pack();
        frame.setVisible(true);
        try { Thread.sleep(3000); }
        catch (InterruptedException e) {}
        Object[][] refresh = { {"five", "E"}, {"six", "F"} };
        model.refreshDataVector( refresh );
}