public DefaultEntitySerializer() 
{
        super();
}

 protected OutputStream doSerialize(HttpDataTransmitter datatransmitter,
    HttpMessage message) throws HttpException, IOException 
{
        Header transferEncodingHeader = message.getFirstHeader(HTTP.TRANSFER_ENCODING);
        Header contentLengthHeader = message.getFirstHeader(HTTP.CONTENT_LEN);
        if (transferEncodingHeader != null) {
            String s = transferEncodingHeader.getValue();
            if (HTTP.CHUNK_CODING.equalsIgnoreCase(s)) {
                if (message.getHttpVersion().lessEquals(HttpVersion.HTTP_1_0)) {
                    throw new ProtocolException(
                            "Chunked transfer encoding not allowed for " + 
                            message.getHttpVersion());
                }
                return new ChunkedOutputStream(datatransmitter);
            } else if (HTTP.IDENTITY_CODING.equalsIgnoreCase(s)) {
                return new IdentityOutputStream(datatransmitter);
            } else {
                throw new ProtocolException(
                        "Unsupported transfer encoding: " + s);
            }
        } else if (contentLengthHeader != null) {
            String s = contentLengthHeader.getValue();
            try {
                long len = Long.parseLong(s);
                return new ContentLengthOutputStream(datatransmitter, len);
            } catch (NumberFormatException e) {
                throw new ProtocolException("Invalid content length: " + s);
            }
        } else {
            return new IdentityOutputStream(datatransmitter); 
        }
}

 public  void serialize(HttpDataTransmitter datatransmitter,
    HttpMessage message,
    HttpEntity entity) throws HttpException, IOException 
{
        if (datatransmitter == null) {
            throw new IllegalArgumentException("HTTP data transmitter may not be null");
        }
        if (message == null) {
            throw new IllegalArgumentException("HTTP message may not be null");
        }
        if (entity == null) {
            throw new IllegalArgumentException("HTTP entity may not be null");
        }
        OutputStream outstream = doSerialize(datatransmitter, message);
        entity.writeTo(outstream);
        outstream.close();
}