public PDFXrefStreamParser(COSStream strm,
    COSDocument doc) throws IOException 
{
        super(strm.getUnfilteredStream());
        setDocument(doc);
        stream = strm;
}

Constructor.

Parameters:

strm - The stream to parse.

doc - The document for the current parsing.

Throws:

IOException - If there is an error initializing the stream.

 public  void parse() throws IOException 
{
        try
        {
            COSArray xrefFormat = (COSArray)stream.getDictionaryObject(COSName.W);
            COSArray indexArray = (COSArray)stream.getDictionaryObject(COSName.INDEX);
            /*
             * If Index doesn't exist, we will use the default values. 
             */
            if(indexArray == null)
            {
                indexArray = new COSArray();
                indexArray.add(COSInteger.ZERO);
                indexArray.add(stream.getDictionaryObject(COSName.SIZE));
            }
            ArrayList objNums = new ArrayList();
            /*
             * Populates objNums with all object numbers available
             */
            Iterator indexIter = indexArray.iterator();
            while(indexIter.hasNext())
            {
                int objID = ((COSInteger)indexIter.next()).intValue();
                int size = ((COSInteger)indexIter.next()).intValue();
                for(int i = 0; i <  size; i++)
                {
                    objNums.add(new Integer(objID + i));
                }
            }
            Iterator objIter = objNums.iterator();
            /*
             * Calculating the size of the line in bytes
             */
            int w0 = xrefFormat.getInt(0);
            int w1 = xrefFormat.getInt(1);
            int w2 = xrefFormat.getInt(2);
            int lineSize = w0 + w1 + w2;
            while(pdfSource.available()  > 0 && objIter.hasNext())
            {
                byte[] currLine = new byte[lineSize];
                pdfSource.read(currLine);
                int type = 0;
                /*
                 * Grabs the number of bytes specified for the first column in 
                 * the W array and stores it.
                 */
                for(int i = 0; i <  w0; i++)
                {
                    type += (currLine[i] & 0x00ff) < <  ((w0 - i - 1)* 8);
                }
                //Need to remember the current objID
                Integer objID = (Integer)objIter.next();
                /*
                 * 3 different types of entries. 
                 */
                switch(type)
                {
                    case 0:
                        /*
                         * Skipping free objects
                         */
                        break;
                    case 1:                   
                        int offset = 0;
                        for(int i = 0; i <  w1; i++)
                        {
                            offset += (currLine[i + w0] & 0x00ff) < <  ((w1 - i - 1) * 8);
                        }
                        int genNum = 0;
                        for(int i = 0; i <  w2; i++)
                        {
                            genNum += (currLine[i + w0 + w1] & 0x00ff) < <  ((w2 - i - 1) * 8);
                        }
                        COSObjectKey objKey = new COSObjectKey(objID.intValue(), genNum);
                        document.setXRef(objKey, offset);
                        break;
                    case 2:
                        /*
                         * These objects are handled by the dereferenceObjects() method
                         * since they're only pointing to object numbers
                         */
                        break;
                    default:
                        break;
                }
            }
        }
        finally
        {
            pdfSource.close();
        }
}

Parses through the unfiltered stream and populates the xrefTable HashMap.