public int doWrite(ByteChunk chunk,
    Response res) throws IOException 
{
        int result = -1;
        if (contentLength  >= 0) {
            if (remaining  > 0) {
                result = chunk.getLength();
                if (result  > remaining) {
                    // The chunk is longer than the number of bytes remaining
                    // in the body; changing the chunk length to the number
                    // of bytes remaining
                    chunk.setBytes(chunk.getBytes(), chunk.getStart(), 
                                   (int) remaining);
                    result = (int) remaining;
                    remaining = 0;
                } else {
                    remaining = remaining - result;
                }
                buffer.doWrite(chunk, res);
            } else {
                // No more bytes left to be written : return -1 and clear the 
                // buffer
                chunk.recycle();
                result = -1;
            }
        } else {
            // If no content length was set, just write the bytes
            buffer.doWrite(chunk, res);
            result = chunk.getLength();
        }
        return result;
}

Write some bytes.

 public long end() throws IOException 
{
        if (remaining  > 0)
            return remaining;
        return 0;
}

End the current request. It is acceptable to write extra bytes using buffer.doWrite during the execution of this method.

 public long getContentLength() 
{
    // ------------------------------------------------------------- Properties
        return contentLength;
}

Get content length.

 public ByteChunk getEncodingName() 
{
        return ENCODING;
}

Return the name of the associated encoding; Here, the value is "identity".

 public long getRemaining() 
{
        return remaining;
}

Get remaining bytes.

 public  void recycle() 
{
        contentLength = -1;
        remaining = 0;
}

Make the filter ready to process the next request.

 public  void setBuffer(OutputBuffer buffer) 
{
        this.buffer = buffer;
}

Set the next buffer in the filter pipeline.

 public  void setResponse(Response response) 
{
        contentLength = response.getContentLengthLong();
        remaining = contentLength;
}

Some filters need additional parameters from the response. All the necessary reading can occur in that method, as this method is called after the response header processing is complete.