JTable cell edits return to original values

Question

Hi
I am making some progress with using AbstractTableModel, however I have a problem whereby any edits that I make to cells within the table are being lost when I add a new row��the original values are re-appearing.
I have searched through the forum looking for a solution but with no success thus far.
I believe that the solution lies with the fireTableDataChanged() method but thus far I have had no success. My problem (I believe) is that I cannot work out how to fire it when a user leaves the newly edited cell.
The method that adds the new rows is shown below and is called from a button on the Frame that houses the jTable. I have tried firing the method from here, hoping that all table edits will persist, but unfortunately they still disappear.
public void fillTable()
        if(c > 0)
            for (int i = 0; i < c; i = i + 1)
                this.setValueAt(((JobItemClass) items.get(i)).getItemNumber(), i, 0);
                this.setValueAt(((JobItemClass) items.get(i)).getDescription(), i, 1);
                this.setValueAt(((JobItemClass) items.get(i)).getCostPerItem(), i, 2);
                this.setValueAt(((JobItemClass) items.get(i)).getQuantity(), i, 3);
    public void addRow()
        newItem = new JobItemClass();   //Create an object to hold the new row defsault values
        newItem.setItemNumber(c + 1);
        newItem.setDescription("");
        newItem.setCostPerItem(0.0);
        newItem.setQuantity(0);
        items.add(c, newItem);          //Add the default object to the array
        c = c + 1;                      //Update the variable holding the array size
        table = new Object[c][4];       //Increase the size of the object that acts as the table
        fireTableRowsInserted(c, c);    //Alert the object acting as the table that there is a new row
        fillTable();                    //Refresh the display to reflect the new row default values      
    }As always, any help greatly appreciated
GB

Answer 1

Thanks again for the replies people.
I decided to edit this message and post updated code which can be seen below. This is a result of re-reading the helpfull advice from both azukov and camickr who took the time to respond to my initial request for help. I still have to work out how to validate user input but am sure that the tableChanged method will be the key.
A simple tutorial also provided great assistance, especially helping eith the implementation of the TableModelListener. I have provided a link to the tutorial here:
http://www.javalobby.org/articles/jtable/
The coding was carried out in netbeans 5.5, libraries have not been included.
Here is my updated code......table model first:
public class MyJobItemTableModel extends AbstractTableModel
    JobItemClass newItem;   //Procides a default record when nothing available
    int jobNo;
    int c;
    ArrayList items;        //Stores the objects that provide the records
    public MyJobItemTableModel(int j)
        jobNo = j;
        items = (new JobAllItems(jobNo)).getItems();
        c = items.size();
    String columnName[] = { "Item Number", "Item Description", "Cost per item", "Quantity" };       
    Class columnType[] = { Integer.class, String.class, Double.class, Integer.class };
    /**************************This method probably now redundant************************
    public void storeCellValue(int row, int col)
        if(col == 0)
            ((JobItemClass) items.get(row)).setItemNumber((Integer) this.getValueAt(row, col));
        if(col == 1)
            ((JobItemClass) items.get(row)).setDescription((String) this.getValueAt(row, col));
        if(col == 2)
            ((JobItemClass) items.get(row)).setCostPerItem((Double) this.getValueAt(row, col));
        if(col == 3)
            ((JobItemClass) items.get(row)).setQuantity((Integer) this.getValueAt(row, col));
    public void addRow()
        c = c + 1;                          //Update the variable holding the array size
        newItem = new JobItemClass();       //Create a default object to fill the new row
        newItem.setItemNumber(c);
        newItem.setDescription("");
        newItem.setCostPerItem(0.0);
        newItem.setQuantity(0);
        items.add(c-1, newItem);
        this.fireTableRowsInserted(c, c);   //Update the display to show the added row.
    public int getColumnCount()
        return 4;
    public int getRowCount()
        return items.size();
    public Object getValueAt(int r, int c)
        JobItemClass jic = (JobItemClass) items.get(r);
        switch(c)
            case 0:
                return jic.getItemNumber();
            case 1:
                return jic.getDescription();
            case 2:
                return jic.getCostPerItem();
            case 3:
                return jic.getQuantity();
            default:
                return new Object();               
    public String getColumnName(int column)
        return columnName[column];
    public Class getColumnClass(int c)
        return columnType[c];
    public boolean hasNoItems()
        if(items.size() == 0)
            return true;
        else
            return false;
    public boolean isCellEditable(int r, int c)
        return true;
    public void setValueAt(Object aValue, int r, int c)
        JobItemClass jic = (JobItemClass) items.get(r);
        switch(c)
            case 0:
                jic.setItemNumber((Integer)aValue);
                break;
            case 1:
                jic.setDescription((String)aValue);
                break;
            case 2:
                jic.setCostPerItem((Double)aValue);
                break;
            case 3:
                jic.setQuantity((Integer)aValue);
                break;              
        fireTableCellUpdated(r, c);
}......and now the view (what the user sees)
public class ViewItems extends javax.swing.JPanel
    protected MyJobItemTableModel myModel;
    /** Creates new form ViewItems */
    public ViewItems()
        initComponents();
    public void createTable(int jobNo)
        myModel = new MyJobItemTableModel(jobNo);
        myModel.addTableModelListener(new ViewItems.ViewItemsTableModelListener());
        jTable1.setModel(myModel);
        //jTable1.setSurrendersFocusOnKeystroke(true);  //not sure what this does
        if (myModel.hasNoItems())
            myModel.addRow();          
        public void run(int jobNo)
            createTable(jobNo);
            try
                UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
                JFrame frame = new JFrame("Invoice Breakdown");
                frame.addWindowListener(new WindowAdapter()
                    public void windowClosing(WindowEvent evt)
                        setVisible(false);
                frame.getContentPane().add(this);
                frame.pack();
                frame.setVisible(true);
            catch (Exception e)
                e.printStackTrace();
        /**This class is required in order to respond to any changes that happen
         * to the table or data within, i.e. the user editing data in a cell.
         * The tablemodel (MyJobItemTableModel) will 'fire' the event and the
         * tableChanged() method will be executed.
        public class ViewItemsTableModelListener implements TableModelListener
            public void tableChanged(TableModelEvent evt)
                if (evt.getType() == TableModelEvent.UPDATE)
                    int column = evt.getColumn();
                    int row = evt.getFirstRow();
                    System.out.println("row: " + row + " column: " + column);
                    jTable1.setColumnSelectionInterval(column + 1, column + 1);
                    jTable1.setRowSelectionInterval(row, row);
        /** This method is called from within the constructor to
         * initialize the form.
         * WARNING: Do NOT modify this code. The content of this method is
         * always regenerated by the Form Editor.
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">                         
    private void initComponents()
        jScrollPane1 = new javax.swing.JScrollPane();
        jTable1 = new javax.swing.JTable();
        btnAddItem = new javax.swing.JButton();
        jTable1.setModel(new javax.swing.table.DefaultTableModel(
            new Object [][]
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null},
                {null, null, null, null}
            new String []
                "Title 1", "Title 2", "Title 3", "Title 4"
        jScrollPane1.setViewportView(jTable1);
        btnAddItem.setText("Add Item");
        btnAddItem.addActionListener(new java.awt.event.ActionListener()
            public void actionPerformed(java.awt.event.ActionEvent evt)
                btnAddItemActionPerformed(evt);
        org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .addContainerGap()
                .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                    .add(layout.createSequentialGroup()
                        .add(jScrollPane1, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 589, Short.MAX_VALUE)
                        .addContainerGap())
                    .add(org.jdesktop.layout.GroupLayout.TRAILING, layout.createSequentialGroup()
                        .add(btnAddItem)
                        .add(264, 264, 264))))
        layout.setVerticalGroup(
            layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(layout.createSequentialGroup()
                .addContainerGap()
                .add(jScrollPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 163, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .add(49, 49, 49)
                .add(btnAddItem)
                .addContainerGap(54, Short.MAX_VALUE))
    }// </editor-fold>                       
    private void btnAddItemActionPerformed(java.awt.event.ActionEvent evt)                                          
        ViewItems.this.myModel.addRow();
    // Variables declaration - do not modify                    
    private javax.swing.JButton btnAddItem;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTable jTable1;
    // End of variables declaration                  
    }Edited by: greenockboy on Oct 15, 2007 8:17 PM