#1
  1. No Profile Picture
    Registered User
    Devshed Newbie (0 - 499 posts)

    Join Date
    Oct 2013
    Posts
    7
    Rep Power
    0

    How to solve Nullpointer exception


    I want to highlight the patterns that are present in my string. For this purpose I have created a database of patterns and stored them in an array. Now I want these patterns to be highlighted in jtextpane and with different colors and I have used if else condition for this purpose that will highlight the patterns with different colors based on the strings that are stored in other arraylist but I am having following exception .

    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at javax.swing.text.DefaultHighlighter.paint(DefaultHighlighter.java:72)
    at javax.swing.plaf.basic.BasicTextUI.paintSafely(BasicTextUI.java:731)
    at javax.swing.plaf.basic.BasicTextUI.paint(BasicTextUI.java:881)
    at javax.swing.plaf.synth.SynthEditorPaneUI.paint(SynthEditorPaneUI.java:180)
    at javax.swing.plaf.synth.SynthEditorPaneUI.update(SynthEditorPaneUI.java:168)
    at javax.swing.JComponent.paintComponent(JComponent.java:778)
    at javax.swing.JComponent.paint(JComponent.java:1054)
    at javax.swing.JComponent.paintToOffscreen(JComponent.java:5219)

    at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1452)
    at javax.swing.RepaintManager.paint(RepaintManager.java:1249)
    at javax.swing.JComponent._paintImmediately(JComponent.java:5167)
    at javax.swing.JComponent.paintImmediately(JComponent.java:4978)
    at javax.swing.RepaintManager$3.run(RepaintManager.java:808)
    at javax.swing.RepaintManager$3.run(RepaintManager.java:796)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:796)
    at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:769)
    at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:718)
    at javax.swing.RepaintManager.access$1100(RepaintManager.java:62)
    at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1677)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:733)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:694)
    at java.awt.EventQueue$3.run(EventQueue.java:692)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:703)
    atjava.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

    This is my code

    Code:
    String seq="aset"; jTextPane2.setText(seq);    for (int i = 0; i < mot.size(); i++) {     if (mot.get(i) == "set") {       myHighlightPainter = new MyHighlightPainter(Color.red);     } else if (mot.get(i) == "get") {       myHighlightPainter = new MyHighlightPainter(Color.green);     }     highlight(jTextPane2, pat.get(i));   }// patterns arraylist }  public void highlight(JTextComponent textComp, String pattern) {    try {     Highlighter hilite = textComp.getHighlighter();     Document doc = textComp.getDocument();     String text = doc.getText(0, doc.getLength());     int pos = 0;      // Search for pattern     // see I have updated now its not case sensitive     while ((pos = text.toUpperCase().indexOf(pattern.toUpperCase(), pos)) >= 0) {       // Create highlighter using private painter and apply around pattern       hilite.addHighlight(pos, pos + pattern.length(), myHighlightPainter);       pos += pattern.length();     }   } catch (BadLocationException e) {   } }
    Any suggestion as to how can I solve this problem?
  2. #2
  3. Contributing User
    Devshed Expert (3500 - 3999 posts)

    Join Date
    Aug 2010
    Location
    Eastern Florida
    Posts
    3,719
    Rep Power
    348
    Also posted at: http://www.java-forums.org/new-java/83211-exception-thread-awt-eventqueue-0-a.html

IMN logo majestic logo threadwatch logo seochat tools logo