public void jButton2_actionPerformed(ActionEvent e)
    {
        DefaultStyledDocument doc_old = (DefaultStyledDocument)this.jTextPane1.getDocument();
       

        DefaultStyledDocument doc = new DefaultStyledDocument();
        
        Element[] es = doc_old.getRootElements();
        for (int i = 0; i < es.length; i++)
        {
            Element root = es[i];
            if (root.getName().equals(DefaultStyledDocument.SectionElementName))
                setElement(doc, doc_old, root);
    
        }

        this.jTextPane1.setDocument(doc);

    }

 
private void setElement(DefaultStyledDocument doc, DefaultStyledDocument doc_old, Element e)
    {
        try
        {
            if (e.isLeaf())
            {
                String text = doc_old.getText(e.getStartOffset(),e.getEndOffset()-e.getStartOffset());
                String tempText = new String(text.getBytes("ISO8859-1"), "GBK");
               
                int len = doc.getLength();
                doc.insertString(len, tempText, e.getAttributes());
            }
            else
            {
                int count = e.getElementCount();
                for (int i = 0; i < count; i++)
                {
                    Element ex = e.getElement(i);
                    setElement(doc, doc_old, ex);
                }
            }
        }
        catch (BadLocationException ex1)
        {
            ex1.printStackTrace();
        }
        catch (UnsupportedEncodingException ex)
        {
            /** @todo Handle this exception */
        }

    }