将获取的字符串转换为输入流，然后通过输出流写到文件上：

    public static int appendFile(String text, OutputStream outStream) throws IOException {                byte[] bs = text.getBytes("UTF-8");    	InputStream in = new ByteArrayInputStream(bs);        try {            int byteCount = 0;            byte[] buffer = new byte[1024];            int bytesRead = -1;            while ((bytesRead = in.read(buffer)) != -1) {                outStream.write(buffer, 0, bytesRead);                byteCount += bytesRead;            }            outStream.flush();            return byteCount;        } finally {            try {                in.close();            } catch (IOException ex) {                LOGGER.warn("Could not close InputStream", ex);            }        }    }