InputStream > String , StringBuffer 변환

String 변환

    public String convertStreamToString(InputStream is)
            throws IOException {
        /*
         * To convert the InputStream to String we use the
         * Reader.read(char[] buffer) method. We iterate until the
         * Reader return -1 which means there's no more data to
         * read. We use the StringWriter class to produce the string.
         */
        if (is != null) {
            Writer writer = new StringWriter();

            char[] buffer = new char[1024];
            try {
                Reader reader = new BufferedReader(
                        new InputStreamReader(is, "UTF-8"));
                int n;
                while ((n = reader.read(buffer)) != -1) {
                    writer.write(buffer, 0, n);
                }
            } finally {
                is.close();
            }
            return writer.toString();
        } else {        
            return "";
        }
    }

StringBuffer 변환

     StringBuffer out = new StringBuffer();
     byte[] b = new byte[4096];
     for (int n; (n = inputStream.read(b)) != -1;) {
         out.append(new String(b, 0, n));
     }
     out.toString();

출처 : http://www.kodejava.org/examples/266.html