Name: jk109818 Date: 10/08/2002


FULL PRODUCT VERSION :
java version "1.4.0"

FULL OPERATING SYSTEM VERSION :

Any OS

EXTRA RELEVANT SYSTEM CONFIGURATION :
Any OS

A DESCRIPTION OF THE PROBLEM :
When navigating using an HTML Editor Pane, sometimes an NPE
is thrown on some web pages. The stack trace shows that
sometimes the Shape object returned is null.

Pseudo-source:

/**
 * Embed this in a swing app
 */
public class HelpView extends JOptionPane {
    
    private String title;
    private JEditorPane editorPane;
    
    /** Creates a new instance of HelpView */
    public HelpView() {
        editorPane = factory.createEditorPane();
        editorPane.setEditable(false);
        editorPane.setPreferredSize(new Dimension(352, 264));
        editorPane.addHyperlinkListener(new
HyperlinkListener() {
            public void hyperlinkUpdate(HyperlinkEvent e) {
                if (e.getEventType() ==
HyperlinkEvent.EventType.ACTIVATED) {
                    setURL(e.getURL());
                }
            }
        });
        JButton closeButton = new JButton("Close");
        // ...code to connect the button to disposal here...
        setOptions(new Object[] { closeButton });
        setInitialValue(closeButton);
        
        JScrollPane scrollPane =
factory.createScrollPane(editorPane);
        setMessage(new Object[] { scrollPane });
    }
    
    /**
     * Sets the page for this view
     */
    public void setURL(URL url) {
        try {
            // We have to parse the document to find the title
            InputStream iStream = url.openStream();
            InputStreamReader reader = new
InputStreamReader(iStream);
            HTMLCallback callback = new HTMLCallback();
            new ParserDelegator().parse(reader, callback, true);
            editorPane.setPage(url);
        } catch (IOException e) {
            e.printStackTrace(); // Remind : Handle 404
        }
    }

    /**
     * Parser callback used to retrieve any information from
the HTML document
     * that we may want to use to update other controls
(such as setting the
     * title of the owning frame).
     */
    private class HTMLCallback extends
HTMLEditorKit.ParserCallback {
        
        boolean isTitle = false;
        
        public void handleStartTag(HTML.Tag t,
MutableAttributeSet a, int pos) {
            if (t == HTML.Tag.TITLE) {
                isTitle = true;
            }
        }
        
        public void handleEndTag(HTML.Tag t, int pos) {
            if (t == HTML.Tag.TITLE) {
                isTitle = false;
            }
        }
        
        public void handleText(char[] data, int pos) {
            if (isTitle) {
                title = new String(data);
            }
        }
    }
 
}


java.lang.NullPointerException

at
javax.swing.text.html.HTMLEditorKit$LinkController.doesElementContainLocation(HTMLEditorKit.java:733)

at
javax.swing.text.html.HTMLEditorKit$LinkController.mouseMoved(HTMLEditorKit.java:631)

at
java.awt.AWTEventMulticaster.mouseMoved(AWTEventMulticaster.java:268)

at
java.awt.Component.processMouseMotionEvent(Component.java:5066)

at
javax.swing.JComponent.processMouseMotionEvent(JComponent.java:2763)

at java.awt.Component.processEvent(Component.java:4822)

at java.awt.Container.processEvent(Container.java:1380)

at java.awt.Component.dispatchEventImpl(Component.java:3526)

at java.awt.Container.dispatchEventImpl(Container.java:1437)

at java.awt.Component.dispatchEvent(Component.java:3367)

at
java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3214)

at
java.awt.LightweightDispatcher.processMouseEvent(Container.java:2942)

at
java.awt.LightweightDispatcher.dispatchEvent(Container.java:2859)

at java.awt.Container.dispatchEventImpl(Container.java:1423)

at java.awt.Window.dispatchEventImpl(Window.java:1566)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)

at
java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)

at
java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)

at
java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:134)

at java.awt.Dialog.show(Dialog.java:524)

at java.awt.Component.show(Component.java:1128)

at java.awt.Component.setVisible(Component.java:1083)

at
com.teleias.gui.action.ShowWindowAction.showWindow(ShowWindowAction.java:190)

at
com.teleias.gui.action.ShowWindowAction.actionPerformed(ShowWindowAction.java:147)

at
javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1767)

at
javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1820)

at
javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:419)

at
javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:257)

at javax.swing.AbstractButton.doClick(AbstractButton.java:289)

at
javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1092)

at
javax.swing.plaf.basic.BasicMenuItemUI$MenuDragMouseHandler.menuDragMouseReleased(BasicMenuItemUI.java:991)

at
javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:582)

at
javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:479)

at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:426)

at
javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:274)

at
javax.swing.plaf.basic.BasicMenuUI$MouseInputHandler.mouseReleased(BasicMenuUI.java:334)

at
java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:227)

at java.awt.Component.processMouseEvent(Component.java:5021)

at java.awt.Component.processEvent(Component.java:4818)

at java.awt.Container.processEvent(Container.java:1380)

at java.awt.Component.dispatchEventImpl(Component.java:3526)

at java.awt.Container.dispatchEventImpl(Container.java:1437)

at java.awt.Component.dispatchEvent(Component.java:3367)

at
java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3214)

at
java.awt.LightweightDispatcher.processMouseEvent(Container.java:2929)

at
java.awt.LightweightDispatcher.dispatchEvent(Container.java:2859)

at java.awt.Container.dispatchEventImpl(Container.java:1423)

at java.awt.Window.dispatchEventImpl(Window.java:1566)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)

at
java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)

at
java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)

at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)

at
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:130)

at java.awt.EventDispatchThread.run(EventDispatchThread.java:98)


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
See description.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.NullPointerException

at
javax.swing.text.html.HTMLEditorKit$LinkController.doesElementContainLocation(HTMLEditorKit.java:733)

at
javax.swing.text.html.HTMLEditorKit$LinkController.mouseMoved(HTMLEditorKit.java:631)

at java.awt.AWTEventMulticaster.mouseMoved(AWTEventMulticaster.java:268)

at java.awt.Component.processMouseMotionEvent(Component.java:5066)

at javax.swing.JComponent.processMouseMotionEvent(JComponent.java:2763)

at java.awt.Component.processEvent(Component.java:4822)

at java.awt.Container.processEvent(Container.java:1380)

at java.awt.Component.dispatchEventImpl(Component.java:3526)

at java.awt.Container.dispatchEventImpl(Container.java:1437)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3214)

at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2942)

at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2859)

at java.awt.Container.dispatchEventImpl(Container.java:1423)

at java.awt.Window.dispatchEventImpl(Window.java:1566)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)

at
java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:134)

at java.awt.Dialog.show(Dialog.java:524)

at java.awt.Component.show(Component.java:1128)

at java.awt.Component.setVisible(Component.java:1083)

at com.teleias.gui.action.ShowWindowAction.showWindow(ShowWindowAction.java:190)

at com.teleias.gui.action.ShowWindowAction.actionPerformed(ShowWindowAction.java:147)

at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1767)

at
javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(AbstractButton.java:1820)

at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:419)

at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:257)

at javax.swing.AbstractButton.doClick(AbstractButton.java:289)

at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1092)

at
javax.swing.plaf.basic.BasicMenuItemUI$MenuDragMouseHandler.menuDragMouseReleased(BasicMenuItemUI.java:991)

at javax.swing.JMenuItem.fireMenuDragMouseReleased(JMenuItem.java:582)

at javax.swing.JMenuItem.processMenuDragMouseEvent(JMenuItem.java:479)

at javax.swing.JMenuItem.processMouseEvent(JMenuItem.java:426)

at javax.swing.MenuSelectionManager.processMouseEvent(MenuSelectionManager.java:274)

at
javax.swing.plaf.basic.BasicMenuUI$MouseInputHandler.mouseReleased(BasicMenuUI.java:334)

at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:227)

at java.awt.Component.processMouseEvent(Component.java:5021)

at java.awt.Component.processEvent(Component.java:4818)

at java.awt.Container.processEvent(Container.java:1380)

at java.awt.Component.dispatchEventImpl(Component.java:3526)

at java.awt.Container.dispatchEventImpl(Container.java:1437)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3214)

at java.awt.LightweightDispatcher.processMouseEvent(Container.java:2929)

at java.awt.LightweightDispatcher.dispatchEvent(Container.java:2859)

at java.awt.Container.dispatchEventImpl(Container.java:1423)

at java.awt.Window.dispatchEventImpl(Window.java:1566)

at java.awt.Component.dispatchEvent(Component.java:3367)

at java.awt.EventQueue.dispatchEvent(EventQueue.java:445)

at
java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:190)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:144)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:130)

at java.awt.EventDispatchThread.run(EventDispatchThread.java:98)



REPRODUCIBILITY :
This bug can be reproduced occasionally.

---------- BEGIN SOURCE ----------
/**
 * Embed this in a swing app
 * Note that this is only pseudo-source and may not compile outside of the
 * context in which it was used.
 */
public class HelpView extends JOptionPane {
    
    private String title;
    private JEditorPane editorPane;
    
    /** Creates a new instance of HelpView */
    public HelpView() {
        editorPane = factory.createEditorPane();
        editorPane.setEditable(false);
        editorPane.setPreferredSize(new Dimension(352, 264));
        editorPane.addHyperlinkListener(new HyperlinkListener() {
            public void hyperlinkUpdate(HyperlinkEvent e) {
                if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
                    setURL(e.getURL());
                }
            }
        });
        JButton closeButton = new JButton("Close");
        // ...code to connect the button to disposal here...
        setOptions(new Object[] { closeButton });
        setInitialValue(closeButton);
        
        JScrollPane scrollPane = factory.createScrollPane(editorPane);
        setMessage(new Object[] { scrollPane });
    }
    
    /**
     * Sets the page for this view
     */
    public void setURL(URL url) {
        try {
            // We have to parse the document to find the title
            InputStream iStream = url.openStream();
            InputStreamReader reader = new InputStreamReader(iStream);
            HTMLCallback callback = new HTMLCallback();
            new ParserDelegator().parse(reader, callback, true);
            editorPane.setPage(url);
        } catch (IOException e) {
            e.printStackTrace(); // Remind : Handle 404
        }
    }

    /**
     * Parser callback used to retrieve any information from the HTML document
     * that we may want to use to update other controls (such as setting the
     * title of the owning frame).
     */
    private class HTMLCallback extends HTMLEditorKit.ParserCallback {
        
        boolean isTitle = false;
        
        public void handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos) {
            if (t == HTML.Tag.TITLE) {
                isTitle = true;
            }
        }
        
        public void handleEndTag(HTML.Tag t, int pos) {
            if (t == HTML.Tag.TITLE) {
                isTitle = false;
            }
        }
        
        public void handleText(char[] data, int pos) {
            if (isTitle) {
                title = new String(data);
            }
        }
    }
 
}


---------- END SOURCE ----------
(Review ID: 164564)
======================================================================