Source Code : How to add rows to JTable with AbstractTableModel method?

How to add rows to JTable with AbstractTableModel method?

import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

class sscce extends JFrame {

private static final long serialVersionUID = 1L;  // Serial ID...

// Interface-Elemente erzeugen
Container content = getContentPane();

DefaultTableModel myAbstractTableModel = new DefaultTableModel () {
  private static final long serialVersionUID = 1L;  // whatever
  public String[] columnNames = {"AuftragNr", "Datum & Uhrzeit", "Von", "Nach", "erledigt?"};
  public Object[][] data = {{"156", "31.12.2012 - 10:39:31", "5/5", "205/39", new Boolean(false)}};

  public int getColumnCount() {
  return columnNames.length;
  }

  public int getRowCount() {
  return data.length;
  }

  public String getColumnName(int col) {
  return columnNames[col];
  }

  public Object getValueAt(int row, int col) {
  return data[row][col];
  }

  public Class getColumnClass(int c) {
  return getValueAt(0, c).getClass();
  }

  public boolean isCellEditable(int row, int col) {
  if (col != 4) {
  return false;
  } else {
  return true;
  }
  }

  public void setValueAt(Object value, int row, int col) {
  data[row][col] = value;
  fireTableCellUpdated(row, col);
  }
};

JTable auftragTable = new JTable(myAbstractTableModel);
JScrollPane tableScrollPane = new JScrollPane(auftragTable);
JButton auftragAenderungSpeichern = new JButton("speichern");

public sscce() {
  setTitle("Auftragsverwaltung");
  setSize(700, 500);
  setLocation(500, 200);
  setLayout(null);
  setResizable(false);
  tableScrollPane.setBounds(50, 50, 500, 200);

  addWindowListener(new WindowAdapter() {
  public void windowClosing(WindowEvent e) {
  System.exit(0);
  }
  });
}

public void actionPerformed(ActionEvent e) {

}

@SuppressWarnings("deprecation")
public static void main(String[] args) {
  JFrame f = new sscce();
  f.show();
}
}
Whenever I try to running the progam, I get a NullPointerException along with

at javax.swing.table.DefaultTableModel.setDataVector(Unknown Source)
at javax.swing.table.DefaultTableModel.(Unknown Source)
at javax.swing.table.DefaultTableModel.(Unknown Source)
at javax.swing.table.DefaultTableModel.(Unknown Source)
for the following line of code:

public int getRowCount() {
  return data.length;
}