What sorting codes to be put to the following below codes so that it displays the Surname together with name in ascending order?

The codes are:

private void btnaddActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: if(txtname.getText().equals("")||txtsurname.getText().equals("")||txtage.getText().equals("")){ JOptionPane.showMessageDialog(this, "Please enter all data"); }else{ String data[]= {txtname.getText(),txtsurname.getText(), txtage.getText() }; DefaultTableModel tblModel= (DefaultTableModel)jTableExport.getModel(); tblModel.addRow(data); JOptionPane.showMessageDialog(this, "Data added successfully"); txtname.setText(""); txtsurname.setText(""); txtage.setText(""); }

}