<Swing Dev> Review rquest for 7055065, NPE from JTable when quit editing with empty value in number culumns

[Jonathan Lu]

Hi Pavel,

Thanks for reviewing, here's the webrev patch and automatic test. Could 
you please help to take another look?
http://cr.openjdk.java.net/~luchsh/7055065/

Thanks & regards!
- Jonathan

On 04/13/2012 05:59 PM, Pavel Porvatov wrote:
> Hi Jonathan,
>
> The fix looks good. Could you please write an automatic test, put it 
> into an appropriate place of repository and make a webrev with fix and 
> test?
>
> Regards, Pavel
>> Hello swing-dev,
>>
>> I've got a patch for bug 7055065, can anybody please help to take a 
>> look?
>> http://cr.openjdk.java.net/~luchsh/7055065/
>>
>> And also a simple test case for this issue here.
>>
>> /*
>>  * Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
>>  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>>  *
>>  * This code is free software; you can redistribute it and/or modify it
>>  * under the terms of the GNU General Public License version 2 only, as
>>  * published by the Free Software Foundation.
>>  *
>>  * This code is distributed in the hope that it will be useful, but 
>> WITHOUT
>>  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
>>  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
>>  * version 2 for more details (a copy is included in the LICENSE file 
>> that
>>  * accompanied this code).
>>  *
>>  * You should have received a copy of the GNU General Public License 
>> version
>>  * 2 along with this work; if not, write to the Free Software 
>> Foundation,
>>  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
>>  *
>>  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 
>> 94065 USA
>>  * or visit www.oracle.com if you need additional information or have 
>> any
>>  * questions.
>>  */
>>
>> /*
>>  * Portions Copyright (c) 2012 IBM Corporation
>>  */
>>
>> import javax.swing.JFrame;
>> import javax.swing.JPanel;
>> import javax.swing.JScrollPane;
>> import javax.swing.JTable;
>> import javax.swing.table.AbstractTableModel;
>> import javax.swing.table.TableModel;
>> import javax.swing.table.TableRowSorter;
>> import java.awt.Dimension;
>> import java.awt.GridLayout;
>>
>> public class TableDemo extends JPanel {
>>
>>     public TableDemo() {
>>         super(new GridLayout(1, 0));
>>
>>         final String[] columnNames = { "String", "Number" };
>>         final Object[][] data = { { "aaaa", new Integer(5) },
>>                 { "bbbb", new Integer(3) }, { "cccc", new Integer(2) },
>>                 { "dddd", new Integer(20) }, { "eeee", new 
>> Integer(10) } };
>>         final JTable table = new JTable(data, columnNames);
>>
>>         table.setPreferredScrollableViewportSize(new Dimension(500, 
>> 400));
>>         table.setFillsViewportHeight(true);
>>         TableModel dataModel = new AbstractTableModel() {
>>
>>             public int getColumnCount() {
>>                 return columnNames.length;
>>             }
>>             public int getRowCount() {
>>                 return data.length;
>>             }
>>             public Object getValueAt(int row, int col) {
>>                 return data[row][col];
>>             }
>>             public String getColumnName(int column) {
>>                 return columnNames[column];
>>             }
>>             public Class<?> getColumnClass(int c) {
>>                 return getValueAt(0, c).getClass();
>>             }
>>             public boolean isCellEditable(int row, int col) {
>>                 return col != 5;
>>             }
>>             public void setValueAt(Object aValue, int row, int column) {
>>                 data[row][column] = aValue;
>>             }
>>         };
>>         table.setModel(dataModel);
>>         TableRowSorter<TableModel> sorter = new 
>> TableRowSorter<TableModel>(
>>                 dataModel);
>>         table.setRowSorter(sorter);
>>
>>         JScrollPane scrollPane = new JScrollPane(table);
>>         add(scrollPane);
>>     }
>>
>>     public static void main(String[] args) throws Exception {
>>         javax.swing.SwingUtilities.invokeAndWait(new Runnable() {
>>             public void run() {
>>                 JFrame frame = new JFrame("SimpleTableDemo");
>>                 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>>
>>                 TableDemo newContentPane = new TableDemo();
>>                 newContentPane.setOpaque(true);
>>                 frame.setContentPane(newContentPane);
>>
>>                 frame.pack();
>>                 frame.setVisible(true);
>>             }
>>         });
>>     }
>> }
>>
>> To reproduce the problem,
>> please click on one cell from the "Number" column, delete all the 
>> content but do not press enter to quit editing status, then click the 
>> column title of "Number" column to sort, NPE will be thrown.
>>
>> The cause of this problem is when trying to quit editing with empty 
>> content of a cell  and also try to accept the partially edited value 
>> using stopCellEditing(), following two actions will be taken.
>> 1, the cellEditor of current table will be set to null.
>> 2, the value type of this column does not have a constructor to 
>> accept "Object[]" parameter, false will be returned.
>> Then swing will try to cancel edition without accepting the partially 
>> edited value using cancelCellEditing() which will get null for the 
>> value of cellEditor thus lead to this NPE.
>>
>> The patch is trying to return earlier before the type compatibility 
>> check of partially edited values when empty cell values encountered.
>>
>> Cheers!
>> - Jonathan
>>
>