PdfReaderInstance(PdfReader reader,
    PdfWriter writer) 
{
    
        this.reader = reader;
        this.writer = writer;
        file = reader.getSafeFile();
        myXref = new int[reader.getXrefSize()];
}

 PdfStream getFormXObject(int pageNumber,
    int compressionLevel) throws IOException 
{
        PdfDictionary page = reader.getPageNRelease(pageNumber);
        PdfObject contents = PdfReader.getPdfObjectRelease(page.get(PdfName.CONTENTS));
        PdfDictionary dic = new PdfDictionary();
        byte bout[] = null;
        if (contents != null) {
            if (contents.isStream())
                dic.putAll((PRStream)contents);
            else
                bout = reader.getPageContent(pageNumber, file);
        }
        else
            bout = new byte[0];
        dic.put(PdfName.RESOURCES, PdfReader.getPdfObjectRelease(page.get(PdfName.RESOURCES)));
        dic.put(PdfName.TYPE, PdfName.XOBJECT);
        dic.put(PdfName.SUBTYPE, PdfName.FORM);
        PdfImportedPage impPage = (PdfImportedPage)importedPages.get(new Integer(pageNumber));
        dic.put(PdfName.BBOX, new PdfRectangle(impPage.getBoundingBox()));
        PdfArray matrix = impPage.getMatrix();
        if (matrix == null)
            dic.put(PdfName.MATRIX, IDENTITYMATRIX);
        else
            dic.put(PdfName.MATRIX, matrix);
        dic.put(PdfName.FORMTYPE, ONE);
        PRStream stream;
        if (bout == null) {
            stream = new PRStream((PRStream)contents, dic);
        }
        else {
            stream = new PRStream(reader, bout, compressionLevel);
            stream.putAll(dic);
        }
        return stream;
}

Gets the content stream of a page as a PdfStream object.

 PdfImportedPage getImportedPage(int pageNumber) 
{
        if (!reader.isOpenedWithFullPermissions())
            throw new IllegalArgumentException("PdfReader not opened with owner password");
        if (pageNumber <  1 || pageNumber  > reader.getNumberOfPages())
            throw new IllegalArgumentException("Invalid page number: " + pageNumber);
        Integer i = new Integer(pageNumber);
        PdfImportedPage pageT = (PdfImportedPage)importedPages.get(i);
        if (pageT == null) {
            pageT = new PdfImportedPage(this, writer, pageNumber);
            importedPages.put(i, pageT);
        }
        return pageT;
}

 int getNewObjectNumber(int number,
    int generation) 
{
        if (myXref[number] == 0) {
            myXref[number] = writer.getIndirectReferenceNumber();
            nextRound.add(new Integer(number));
        }
        return myXref[number];
}

 PdfReader getReader() 
{
        return reader;
}

 RandomAccessFileOrArray getReaderFile() 
{
        return file;
}

 PdfObject getResources(int pageNumber) 
{
        PdfObject obj = PdfReader.getPdfObjectRelease(reader.getPageNRelease(pageNumber).get(PdfName.RESOURCES));
        return obj;
}

  void writeAllPages() throws IOException 
{
        try {
            file.reOpen();
            for (Iterator it = importedPages.values().iterator(); it.hasNext();) {
                PdfImportedPage ip = (PdfImportedPage)it.next();
                writer.addToBody(ip.getFormXObject(writer.getCompressionLevel()), ip.getIndirectReference());
            }
            writeAllVisited();
        }
        finally {
            try {
                reader.close();
                file.close();
            }
            catch (Exception e) {
                //Empty on purpose
            }
        }
}

  void writeAllVisited() throws IOException 
{
        while (!nextRound.isEmpty()) {
            ArrayList vec = nextRound;
            nextRound = new ArrayList();
            for (int k = 0; k <  vec.size(); ++k) {
                Integer i = (Integer)vec.get(k);
                if (!visited.containsKey(i)) {
                    visited.put(i, null);
                    int n = i.intValue();
                    writer.addToBody(reader.getPdfObjectRelease(n), myXref[n]);
                }
            }
        }
}