public int doWrite(ByteChunk chunk,
    Response res) throws IOException 
{
            if (!response.isCommitted()) {
                // Validate and write response headers
                try {
                    prepareResponse();
                } catch (IOException e) {
                    // Set error flag
                    error = true;
                }
            }
            int len = chunk.getLength();
            // 4 - hardcoded, byte[] marshalling overhead
            int chunkSize = Constants.MAX_SEND_SIZE;
            int off = 0;
            while (len  > 0) {
                int thisTime = len;
                if (thisTime  > chunkSize) {
                    thisTime = chunkSize;
                }
                len -= thisTime;
                if (outputBuffer.position() + thisTime +
                    Constants.H_SIZE + 4  > outputBuffer.capacity()) {
                    flush();
                }
                outputBuffer.put((byte) 0x41);
                outputBuffer.put((byte) 0x42);
                outputBuffer.putShort((short) (thisTime + 4));
                outputBuffer.put(Constants.JK_AJP13_SEND_BODY_CHUNK);
                outputBuffer.putShort((short) thisTime);
                outputBuffer.put(chunk.getBytes(), chunk.getOffset() + off, thisTime);
                outputBuffer.put((byte) 0x00);
                off += thisTime;
            }
            return chunk.getLength();
}

Write chunk.