重复读取request中的inputstream

   public RequestWrapper(HttpServletRequest request) {
        int contentLength = request.getContentLength();
        StringBuilder stringBuilder = new StringBuilder();
        InputStream inputStream = null;
        try {
            inputStream = request.getInputStream();
        } catch (IOException e) {
        }
        if (inputStream != null) {
            try (BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream))) {
                char[] charBuffer = new char[contentLength];
                int bytesRead;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } catch (IOException e) {
            }
        } else {
            stringBuilder.append("");
        }
        body = stringBuilder.toString();
    }
    public ServletInputStream getInputStream() throws IOException {

        return new ServletInputStreamWrapper(new ByteArrayInputStream(body.getBytes()));

    }
}