How do I modify a Html tag attribute?

Question

Hi.
I tryed to modify the witdth and height attributes of <applet> tag but I have not obtained it. I run this:
import java.io.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
import javax.swing.text.html.parser.*;
class OtraPrueba{
     public static void main(String[] args){
          String infile = "c:\\Page1.htm";
          String outfile = "c:\\outPage1.htm";
          String applethtml = "<applet code=\"class1.class\" codebase=\"v_10\" width=\"100\" height=\"100\" archive=\"class1.zip\"";
          Reader r;
          Writer w;
          HTMLDocument htmldoc;
          HTMLEditorKit kit = new HTMLEditorKit();
          HTMLEditorKit.ParserCallback callback =          
               new HTMLEditorKit.ParserCallback(){
                    public void handleText(char[] data, int pos){
                         for(int i=0;i<data.length;i++)
                              System.out.println ("data[" + i + "]" + data);
                    public void handleStartTag(HTML.Tag t, MutableAttributeSet a, int pos){
     System.out.println ("handleStartTag " + t);
     if (t == HTML.Tag.APPLET){
          a.removeAttribute(HTML.Attribute.WIDTH);
          a.addAttribute(HTML.Attribute.WIDTH, "100");
          try{
               r = new FileReader(infile);
               w = new FileWriter(outfile);
               System.out.println ("antes del parser");
               new ParserDelegator().parse(r, callback, false);               
Can you help me?
Thanks.

Answer 1

Hello uhilger.
I do it what you tell me last week but I get a NullPointerException at write the document extends HTMLDocument. It seems tries to write a empty tag. this is the exception text:
_______________________exception text_____________________________
java.lang.NullPointerException
at javax.swing.text.AbstractWriter.write(AbstractWriter.java:489)
at javax.swing.text.html.HTMLWriter.emptyTag(HTMLWriter.java:315)
at javax.swing.text.html.HTMLWriter.write(HTMLWriter.java:187)
at javax.swing.text.html.HTMLEditorKit.write(HTMLEditorKit.java:289)
at Editor.setAppletAttributes(Editor.java:1017)
at Editor.saveMenuItemActionPerformed(Editor.java:535)
at Editor.access$13(Editor.java:24)
at Editor$14.actionPerformed(Editor.java:421)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:17
67)
at javax.swing.AbstractButton$ForwardActionEvents.actionPerformed(Abstra
ctButton.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:1
092)
at javax.swing.plaf.basic.BasicMenuItemUI$MouseInputHandler.mouseRelease
d(BasicMenuItemUI.java:932)
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(EventDispatchTh
read.java:190)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
ad.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)
___________________end_exception text_____________________________
I make a subclass of HTMLDocument with name EditableHTMLDocument :
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.text.html.HTMLDocument;
class EditableHTMLDocument extends HTMLDocument{
     public void addAttributes(Element e, AttributeSet a) {
          if ((e != null) && (a != null)) {
               try {
                    writeLock();
                    System.out.println("SHTMLDocument addAttributes e=" + e);
                    System.out.println("SHTMLDocument addAttributes a=" + a);
                    int start = e.getStartOffset();
                    javax.swing.text.AbstractDocument.DefaultDocumentEvent changes =
                    new javax.swing.text.AbstractDocument.DefaultDocumentEvent(start, e.getEndOffset() - start,
                         DocumentEvent.EventType.CHANGE);
                    AttributeSet sCopy = a.copyAttributes();
                    MutableAttributeSet attr = (MutableAttributeSet) e.getAttributes();
                    changes.addEdit(new AttributeUndoableEdit(e, sCopy, false));
                    attr.addAttributes(a);
                    changes.end();
                    fireChangedUpdate(changes);
                    fireUndoableEditUpdate(new UndoableEditEvent(this, changes));
               }finally {
                    writeUnlock();
And this is the method of program main class than call you addAttributes method:
     private void setAppletAttributes(){
          BufferedReader br;
          BufferedWriter bw;
          HTMLDocument htmlDoc;
          EditableHTMLDocument editHtmlDoc;
          HTMLEditorKit kit = new HTMLEditorKit();
          try{          
               br = new BufferedReader( new FileReader( jTxtHtmlFile.getText() ) );
               //htmlDoc = (HTMLDocument)kit.createDefaultDocument ();
               editHtmlDoc = new EditableHTMLDocument();
               kit.read (br, editHtmlDoc, 0);
               br.close ();
               javax.swing.text.Element rootElem = editHtmlDoc.getDefaultRootElement ();
               javax.swing.text.Element elem =
                    editHtmlDoc.getElement (rootElem, HTML.Attribute.CODEBASE, jTxtCodebase.getText ());
               SimpleAttributeSet sas = new SimpleAttributeSet();
               sas.addAttribute ( HTML.Attribute.CODE, jTxtCode.getText () );
               sas.addAttribute ( HTML.Attribute.CODEBASE, jTxtCodebase.getText () );
               sas.addAttribute ( HTML.Attribute.ARCHIVE, jTxtArchive.getText () );
               sas.addAttribute ( HTML.Attribute.WIDTH, jTxtAnchoApplet.getText () );
               sas.addAttribute ( HTML.Attribute.HEIGHT, jTxtAltoApplet.getText () );
               editHtmlDoc.addAttributes (elem, sas);
               editHtmlDoc.dump (System.out);
               bw = new BufferedWriter( new FileWriter( jTxtHtmlFile.getText() ) );
               System.out.println ("length " + editHtmlDoc.getLength ());
               kit.write (bw, editHtmlDoc, 0, editHtmlDoc.getLength ());
               bw.flush ();
               bw.close ();
          }catch(BadLocationException ble){
               System.out.println ("BadLocationException " + ble.getMessage());     
}catch(FileNotFoundException fnfe){
               System.out.println ("FileNotFoundException " + fnfe.getMessage());     
          }catch(IOException ioe){
               System.out.println ("IOException " + ioe.getMessage());
Which you think that it is the problem?
Thank you.
Sergio Mart�n
I visited your great page and download your SimplyHTML. I'll probe later.