public COSWriter(OutputStream os) 
{
        super();
        setOutput(os);
        setStandardOutput(new COSStandardOutputStream(getOutput()));
        formatDecimal.setMaximumFractionDigits( 10 );
        formatDecimal.setGroupingUsed( false );
}

COSWriter constructor comment.

Parameters:

os - The wrapped output stream.

 protected  void addXRefEntry(COSWriterXRefEntry entry) 
{
        getXRefEntries().add(entry);
}

add an entry in the x ref table for later dump.

 public  void close() throws IOException 
{
        if (getStandardOutput() != null)
        {
            getStandardOutput().close();
        }
        if (getOutput() != null)
        {
            getOutput().close();
        }
}

This will close the stream.

 protected  void doWriteBody(COSDocument doc) throws IOException, COSVisitorException 
{
        COSDictionary trailer = doc.getTrailer();
        COSDictionary root = (COSDictionary)trailer.getDictionaryObject( COSName.ROOT );
        COSDictionary info = (COSDictionary)trailer.getDictionaryObject( COSName.INFO );
        COSDictionary encrypt = (COSDictionary)trailer.getDictionaryObject( COSName.ENCRYPT );
        if( root != null )
        {
            addObjectToWrite( root );
        }
        if( info != null )
        {
            addObjectToWrite( info );
        }
        while( objectsToWrite.size()  > 0 )
        {
            COSBase nextObject = (COSBase)objectsToWrite.remove( 0 );
            doWriteObject( nextObject );
        }
        willEncrypt = false;
        if( encrypt != null )
        {
            addObjectToWrite( encrypt );
        }
        while( objectsToWrite.size()  > 0 )
        {
            COSBase nextObject = (COSBase)objectsToWrite.remove( 0 );
            doWriteObject( nextObject );
        }
        // write all objects
        /**
        for (Iterator i = doc.getObjects().iterator(); i.hasNext();)
        {
            COSObject obj = (COSObject) i.next();
            doWriteObject(obj);
        }**/
}

This will write the body of the document.

 protected  void doWriteHeader(COSDocument doc) throws IOException 
{
        getStandardOutput().write( doc.getHeaderString().getBytes() );
        getStandardOutput().writeEOL();
        getStandardOutput().write(COMMENT);
        getStandardOutput().write(GARBAGE);
        getStandardOutput().writeEOL();
}

This will write the header to the PDF document.

 public  void doWriteObject(COSBase obj) throws COSVisitorException 
{
        try
        {
            writtenObjects.add( obj );
            // find the physical reference
            currentObjectKey = getObjectKey( obj );
            // add a x ref entry
            addXRefEntry( new COSWriterXRefEntry(getStandardOutput().getPos(), obj, currentObjectKey));
            // write the object
            getStandardOutput().write(String.valueOf(currentObjectKey.getNumber()).getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(String.valueOf(currentObjectKey.getGeneration()).getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(OBJ);
            getStandardOutput().writeEOL();
            obj.accept( this );
            getStandardOutput().writeEOL();
            getStandardOutput().write(ENDOBJ);
            getStandardOutput().writeEOL();
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

This will write a COS object.

 protected  void doWriteTrailer(COSDocument doc) throws IOException, COSVisitorException 
{
        getStandardOutput().write(TRAILER);
        getStandardOutput().writeEOL();
        COSDictionary trailer = doc.getTrailer();
        //sort xref, needed only if object keys not regenerated
        Collections.sort(getXRefEntries());
        COSWriterXRefEntry lastEntry = (COSWriterXRefEntry)getXRefEntries().get( getXRefEntries().size()-1);
        trailer.setInt(COSName.SIZE, (int)lastEntry.getKey().getNumber()+1);
        trailer.removeItem( COSName.PREV );
        /**
        COSObject catalog = doc.getCatalog();
        if (catalog != null)
        {
            trailer.setItem(COSName.getPDFName("Root"), catalog);
        }
        */
        trailer.accept(this);
        getStandardOutput().write(STARTXREF);
        getStandardOutput().writeEOL();
        getStandardOutput().write(String.valueOf(getStartxref()).getBytes());
        getStandardOutput().writeEOL();
        getStandardOutput().write(EOF);
}

This will write the trailer to the PDF document.

 protected  void doWriteXRef(COSDocument doc) throws IOException 
{
        String offset;
        String generation;
        // sort xref, needed only if object keys not regenerated
        Collections.sort(getXRefEntries());
        COSWriterXRefEntry lastEntry = (COSWriterXRefEntry)getXRefEntries().get( getXRefEntries().size()-1 );
        // remember the position where x ref is written
        setStartxref(getStandardOutput().getPos());
        //
        getStandardOutput().write(XREF);
        getStandardOutput().writeEOL();
        // write start object number and object count for this x ref section
        // we assume starting from scratch
        getStandardOutput().write(String.valueOf(0).getBytes());
        getStandardOutput().write(SPACE);
        getStandardOutput().write(String.valueOf(lastEntry.getKey().getNumber() + 1).getBytes());
        getStandardOutput().writeEOL();
        // write initial start object with ref to first deleted object and magic generation number
        offset = formatXrefOffset.format(0);
        generation = formatXrefGeneration.format(65535);
        getStandardOutput().write(offset.getBytes());
        getStandardOutput().write(SPACE);
        getStandardOutput().write(generation.getBytes());
        getStandardOutput().write(SPACE);
        getStandardOutput().write(XREF_FREE);
        getStandardOutput().writeCRLF();
        // write entry for every object
        long lastObjectNumber = 0;
        for (Iterator i = getXRefEntries().iterator(); i.hasNext();)
        {
            COSWriterXRefEntry entry = (COSWriterXRefEntry) i.next();
            while( lastObjectNumber< entry.getKey().getNumber()-1 )
            {
                offset = formatXrefOffset.format(0);
                generation = formatXrefGeneration.format(65535);
                getStandardOutput().write(offset.getBytes());
                getStandardOutput().write(SPACE);
                getStandardOutput().write(generation.getBytes());
                getStandardOutput().write(SPACE);
                getStandardOutput().write(XREF_FREE);
                getStandardOutput().writeCRLF();
                lastObjectNumber++;
            }
            lastObjectNumber = entry.getKey().getNumber();
            offset = formatXrefOffset.format(entry.getOffset());
            generation = formatXrefGeneration.format(entry.getKey().getGeneration());
            getStandardOutput().write(offset.getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(generation.getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(entry.isFree() ? XREF_FREE : XREF_USED);
            getStandardOutput().writeCRLF();
        }
}

write the x ref section for the pdf file currently, the pdf is reconstructed from the scratch, so we write a single section todo support for incremental writing?

 protected long getNumber() 
{
        return number;
}

This will get the current object number.

 public Map getObjectKeys() 
{
        return objectKeys;
}

This will get all available object keys.

 protected OutputStream getOutput() 
{
        return output;
}

This will get the output stream.

 protected COSStandardOutputStream getStandardOutput() 
{
        return standardOutput;
}

This will get the standard output stream.

 protected long getStartxref() 
{
        return startxref;
}

This will get the current start xref.

 protected List getXRefEntries() 
{
        return xRefEntries;
}

This will get the xref entries.

 protected  void setNumber(long newNumber) 
{
        number = newNumber;
}

This will set the current object number.

 protected  void setStartxref(long newStartxref) 
{
        startxref = newStartxref;
}

This will set the start xref.

 public Object visitFromArray(COSArray obj) throws COSVisitorException 
{
        try
        {
            int count = 0;
            getStandardOutput().write(ARRAY_OPEN);
            for (Iterator i = obj.iterator(); i.hasNext();)
            {
                COSBase current = (COSBase) i.next();
                if( current instanceof COSDictionary )
                {
                    addObjectToWrite( current );
                    writeReference( current );
                }
                else if( current instanceof COSObject )
                {
                    COSBase subValue = ((COSObject)current).getObject();
                    if( subValue instanceof COSDictionary || subValue == null )
                    {
                        addObjectToWrite( current );
                        writeReference( current );
                    }
                    else
                    {
                        subValue.accept( this );
                    }
                }
                else if( current == null )
                {
                    COSNull.NULL.accept( this );
                }
                else
                {
                    current.accept(this);
                }
                count++;
                if (i.hasNext())
                {
                    if (count % 10 == 0)
                    {
                        getStandardOutput().writeEOL();
                    }
                    else
                    {
                        getStandardOutput().write(SPACE);
                    }
                }
            }
            getStandardOutput().write(ARRAY_CLOSE);
            getStandardOutput().writeEOL();
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromArray method comment.

 public Object visitFromBoolean(COSBoolean obj) throws COSVisitorException 
{
        try
        {
            obj.writePDF( getStandardOutput() );
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromBoolean method comment.

 public Object visitFromDictionary(COSDictionary obj) throws COSVisitorException 
{
        try
        {
            getStandardOutput().write(DICT_OPEN);
            getStandardOutput().writeEOL();
            for (Map.Entry< COSName, COSBase > entry : obj.entrySet())
            {
                COSBase value = entry.getValue();
                if (value != null)
                {
                    entry.getKey().accept(this);
                    getStandardOutput().write(SPACE);
                    if( value instanceof COSDictionary )
                    {
                        addObjectToWrite( value );
                        writeReference( value );
                    }
                    else if( value instanceof COSObject )
                    {
                        COSBase subValue = ((COSObject)value).getObject();
                        if( subValue instanceof COSDictionary || subValue == null )
                        {
                            addObjectToWrite( value );
                            writeReference( value );
                        }
                        else
                        {
                            subValue.accept( this );
                        }
                    }
                    else
                    {
                        value.accept(this);
                    }
                    getStandardOutput().writeEOL();
                }
                else
                {
                    //then we won't write anything, there are a couple cases
                    //were the value of an entry in the COSDictionary will
                    //be a dangling reference that points to nothing
                    //so we will just not write out the entry if that is the case
                }
            }
            getStandardOutput().write(DICT_CLOSE);
            getStandardOutput().writeEOL();
            return null;
        }
        catch( IOException e )
        {
            throw new COSVisitorException(e);
        }
}

visitFromDictionary method comment.

 public Object visitFromDocument(COSDocument doc) throws COSVisitorException 
{
        try
        {
            doWriteHeader(doc);
            doWriteBody(doc);
            doWriteXRef(doc);
            doWriteTrailer(doc);
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

The visit from document method.

 public Object visitFromFloat(COSFloat obj) throws COSVisitorException 
{
        try
        {
            obj.writePDF( getStandardOutput() );
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromFloat method comment.

 public Object visitFromInt(COSInteger obj) throws COSVisitorException 
{
        try
        {
            obj.writePDF( getStandardOutput() );
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromFloat method comment.

 public Object visitFromName(COSName obj) throws COSVisitorException 
{
        try
        {
            obj.writePDF( getStandardOutput() );
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromName method comment.

 public Object visitFromNull(COSNull obj) throws COSVisitorException 
{
        try
        {
            obj.writePDF( getStandardOutput() );
            return null;
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromNull method comment.

 public Object visitFromStream(COSStream obj) throws COSVisitorException 
{
        try
        {
            if(willEncrypt)
            {
                document.getSecurityHandler().decryptStream(
                    obj,
                    currentObjectKey.getNumber(),
                    currentObjectKey.getGeneration());
            }
            InputStream input = obj.getFilteredStream();
            // set the length of the stream and write stream dictionary
            COSObject lengthObject = new COSObject( null );
            obj.setItem(COSName.LENGTH, lengthObject);
            //obj.accept(this);
            // write the stream content
            visitFromDictionary( obj );
            getStandardOutput().write(STREAM);
            getStandardOutput().writeCRLF();
            byte[] buffer = new byte[1024];
            int amountRead = 0;
            int totalAmountWritten = 0;
            while( (amountRead = input.read(buffer,0,1024)) != -1 )
            {
                getStandardOutput().write( buffer, 0, amountRead );
                totalAmountWritten += amountRead;
            }
            lengthObject.setObject( COSInteger.get( totalAmountWritten ) );
            getStandardOutput().writeCRLF();
            getStandardOutput().write(ENDSTREAM);
            getStandardOutput().writeEOL();
            return null;
        }
        catch( Exception e )
        {
            throw new COSVisitorException(e);
        }
}

visitFromStream method comment.

 public Object visitFromString(COSString obj) throws COSVisitorException 
{
        try
        {
            if(willEncrypt)
            {
                document.getSecurityHandler().decryptString(
                    obj,
                    currentObjectKey.getNumber(),
                    currentObjectKey.getGeneration());
            }
            obj.writePDF( getStandardOutput() );
        }
        catch (Exception e)
        {
            throw new COSVisitorException(e);
        }
        return null;
}

visitFromString method comment.

 public  void write(COSDocument doc) throws COSVisitorException 
{
        PDDocument pdDoc = new PDDocument( doc );
        write( pdDoc );
}

This will write the pdf document.

 public  void write(PDDocument doc) throws COSVisitorException 
{
        document = doc;
        // if the document says we should remove encryption, then we shouldn't encrypt
        if(doc.isAllSecurityToBeRemoved())
        {
            this.willEncrypt = false;
            // also need to get rid of the "Encrypt" in the trailer so readers 
            // don't try to decrypt a document which is not encrypted
            COSDocument cosDoc = doc.getDocument();
            COSDictionary trailer = cosDoc.getTrailer();
            trailer.removeItem(COSName.ENCRYPT);
        }
        else
        {
            SecurityHandler securityHandler = document.getSecurityHandler();
            if(securityHandler != null)
            {
                try
                {
                    securityHandler.prepareDocumentForEncryption(document);
                    this.willEncrypt = true;
                }
                catch(IOException e)
                {
                    throw new COSVisitorException( e );
                }
                catch(CryptographyException e)
                {
                    throw new COSVisitorException( e );
                }
            }
            else
            {
                    this.willEncrypt = false;
            }        
        }
        COSDocument cosDoc = document.getDocument();
        COSDictionary trailer = cosDoc.getTrailer();
        COSArray idArray = (COSArray)trailer.getDictionaryObject( COSName.ID );
        if( idArray == null )
        {
            try
            {
                //algothim says to use time/path/size/values in doc to generate
                //the id.  We don't have path or size, so do the best we can
                MessageDigest md = MessageDigest.getInstance( "MD5" );
                md.update( Long.toString( System.currentTimeMillis()).getBytes() );
                COSDictionary info = (COSDictionary)trailer.getDictionaryObject( COSName.INFO );
                if( info != null )
                {
                    Iterator values = info.getValues().iterator();
                    while( values.hasNext() )
                    {
                        md.update( values.next().toString().getBytes() );
                    }
                }
                idArray = new COSArray();
                COSString id = new COSString( md.digest() );
                idArray.add( id );
                idArray.add( id );
                trailer.setItem( COSName.ID, idArray );
            }
            catch( NoSuchAlgorithmException e )
            {
                throw new COSVisitorException( e );
            }
        }
        /*
        List objects = doc.getObjects();
        Iterator iter = objects.iterator();
        long maxNumber = 0;
        while( iter.hasNext() )
        {
            COSObject object = (COSObject)iter.next();
            if( object.getObjectNumber() != null &&
                object.getGenerationNumber() != null )
            {
                COSObjectKey key = new COSObjectKey( object.getObjectNumber().longValue(),
                                                     object.getGenerationNumber().longValue() );
                objectKeys.put( object.getObject(), key );
                objectKeys.put( object, key );
                maxNumber = Math.max( key.getNumber(), maxNumber );
                setNumber( maxNumber );
            }
        }*/
        cosDoc.accept(this);
}

This will write the pdf document.

 public  void writeReference(COSBase obj) throws COSVisitorException 
{
        try
        {
            COSObjectKey  key = getObjectKey(obj);
            getStandardOutput().write(String.valueOf(key.getNumber()).getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(String.valueOf(key.getGeneration()).getBytes());
            getStandardOutput().write(SPACE);
            getStandardOutput().write(REFERENCE);
        }
        catch (IOException e)
        {
            throw new COSVisitorException(e);
        }
}

visitFromObjRef method comment.