Hardcore exception stacktrace related to long message in JDialog

Question

Hi,
Here's the code for my showDialog method:
    void showDialog(String title, String messageContent) {
        String output = "<font face=\"Arial, sans-serif, Helvetica, Geneva\">" + messageContent;
        //output = output.substring(0, 254); Works with 254. 255+ creates the problem.
        //System.out.print(output); outputs correctly, even with very very long strings
        JPanel panel = new JPanel(new BorderLayout());
        JTextPane message = new JTextPane();
        message.setEditable(false);
        message.setContentType("text/html");
        message.setBackground(lightGray);
        message.setHighlighter(null);
        message.setPreferredSize(new Dimension(250, 150));
        message.setText(output);
        //System.out.println(message + "\n--------\n"); //not null
        panel.add(message, BorderLayout.CENTER);
        JDialog dialog = new JDialog(frame, title);
        //System.out.println(dialog + "\n--------\n"); //not null
        dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        dialog.setSize(250, 200);
        dialog.setLocationRelativeTo(frame);
        dialog.setContentPane(panel);
        dialog.show();
    }It works as expected for relatively short Strings (messageContent). Once I try to display my dialogs with more content in it (Strings of length 255+), shit hits the fan:
java.lang.NullPointerException
        at javax.swing.text.GlyphView.paint(GlyphView.java:367)
        at javax.swing.text.BoxView.paintChild(BoxView.java:144)
        at javax.swing.text.BoxView.paint(BoxView.java:407)
        at javax.swing.text.BoxView.paintChild(BoxView.java:144)
        at javax.swing.text.BoxView.paint(BoxView.java:407)
        at javax.swing.text.ParagraphView.paint(ParagraphView.java:569)
        at javax.swing.text.html.ParagraphView.paint(ParagraphView.java:220)
        at javax.swing.text.BoxView.paintChild(BoxView.java:144)
        at javax.swing.text.BoxView.paint(BoxView.java:407)
        at javax.swing.text.html.BlockView.paint(BlockView.java:264)
        at javax.swing.text.BoxView.paintChild(BoxView.java:144)
        at javax.swing.text.BoxView.paint(BoxView.java:407)
        at javax.swing.text.html.BlockView.paint(BlockView.java:264)
        at javax.swing.plaf.basic.BasicTextUI$RootView.paint(BasicTextUI.java:1319)
        at javax.swing.plaf.basic.BasicTextUI.paintSafely(BasicTextUI.java:636)
        at javax.swing.plaf.basic.BasicTextUI.paint(BasicTextUI.java:770)
        at javax.swing.plaf.basic.BasicTextUI.update(BasicTextUI.java:749)
        at javax.swing.JComponent.paintComponent(JComponent.java:541)
        at javax.swing.JComponent.paint(JComponent.java:808)
        at javax.swing.JComponent.paintChildren(JComponent.java:647)
        at javax.swing.JComponent.paint(JComponent.java:817)
        at javax.swing.JComponent.paintChildren(JComponent.java:647)
        at javax.swing.JComponent.paint(JComponent.java:817)
        at javax.swing.JLayeredPane.paint(JLayeredPane.java:557)
        at javax.swing.JComponent.paintChildren(JComponent.java:647)
        at javax.swing.JComponent.paintWithOffscreenBuffer(JComponent.java:4794)
        at javax.swing.JComponent.paintDoubleBuffered(JComponent.java:4740)
        at javax.swing.JComponent.paint(JComponent.java:798)
        at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:21)
        at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:60)
        at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:97)
        at java.awt.Container.paint(Container.java:1312)
        at sun.awt.RepaintArea.paint(RepaintArea.java:177)
        at sun.awt.windows.WComponentPeer.handleEvent(WComponentPeer.java:260)
        at java.awt.Component.dispatchEventImpl(Component.java:3678)
        at java.awt.Container.dispatchEventImpl(Container.java:1627)
        at java.awt.Window.dispatchEventImpl(Window.java:1606)
        at java.awt.Component.dispatchEvent(Component.java:3477)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
        at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)This error message isn't really helping me. :(
Might any of you gurus have a clue what the problem is, and what I can do about it?

Answer 1

Hi, the message is not with 255 characters limit I think. Is there a function called paint overridded in your class? Textpane takes around 65556 chars.