public Buffer(Factory factory,
    String contentType,
    String encoding) 
{
           
        this.encoding = encoding;
        pageParser = factory.getPageParser(contentType);
}

 public ServletOutputStream getOutputStream() 
{
        if (bufferedStream == null) {
            if (bufferedWriter != null) {
                throw new IllegalStateException("response.getOutputStream() called after response.getWriter()");
            }
            bufferedStream = new FastByteArrayOutputStream();
            exposedStream = new ServletOutputStream() {
                public void write(int b) {
                    bufferedStream.write(b);
                }
            };
        }
        return exposedStream;
}

 public PrintWriter getWriter() 
{
        if (bufferedWriter == null) {
            if (bufferedStream != null) {
                throw new IllegalStateException("response.getWriter() called after response.getOutputStream()");
            }
            bufferedWriter = new CharArrayWriter(128);
            exposedWriter = new PrintWriter(bufferedWriter);
        }
        return exposedWriter;
}

 public boolean isUsingStream() 
{
        return bufferedStream != null;
}

 public Page parse() throws IOException 
{
        if (bufferedWriter != null) {
            return pageParser.parse(bufferedWriter.toCharArray());
        } else if (bufferedStream != null) {
            return pageParser.parse(TEXT_ENCODER.encode(bufferedStream.toByteArray(), encoding));
        } else {
            return pageParser.parse(new char[0]);
        }
}