How do I save a file downloaded with HttpClient into a specific folder

I am trying to download a PDF file with HttpClient. I am able to get the file but i am not sure how to convert the bytes into a a PDF and store it somewhere on the system

I have the following code, How can I store it as a PDF?

 public ???? getFile(String url) throws ClientProtocolException, IOException{

            HttpGet httpget = new HttpGet(url);
            HttpResponse response = httpClient.execute(httpget);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                long len = entity.getContentLength();
                InputStream inputStream = entity.getContent();
                // How do I write it?
            }

            return null;
        }