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Programming and Scripting => Java => : Psycho_Coder May 17, 2015, 08:56:16 PM

: [Question] Download Attachments or Files from Websites with Java and HttpClient
: Psycho_Coder May 17, 2015, 08:56:16 PM

Hello Everyone,

I am having a little problem while downloading a file from a site.

Aim

Download a File (named MyContacts.xls) from a site after logging into the site.

My Approach

1. Login to the Site and store the Session IDs and cookies. ConnectionManager is a class which manages the login process in my code and stores the cookies or session id.

2. http://site.com/ExportContacts?Token=<Some-Token-ID>, this is the url which when I visit after logging into the site manually the file MyContactc.xls is downloaded. I want to download this using code.

3. I sent a POST request and set the headers as required. I observed the headers by inspecting the webpage and monitoring the requests sent under the network tab in Chrome.

(http://i.imgur.com/8eTQS8I.png)

(http://i.imgur.com/ktQpj4n.png)

These are the Request and Response Headers. In the second image the form data I am primarily interested in that data which is downloaded as xls file. But I am unable to get the data as well. Whatever I am more concerned with downloading the file using Code.

Libraries Used

Apache HttpClient

Below is the main snippet where I am trying to download the file.

: (java)

try {
            ConnectionManager conMan = new ConnectionManager("Some Username", "Some Password");
            conMan.login();

            HttpClient client = HttpClientBuilder.create().build();

            HttpPost post = new HttpPost("http://site.com/ExportContacts");

            post.setHeader("User-Agent", Utils.USERAGENT.getValue());
            post.setHeader("Content-Type", "application/msexcel");
            post.setHeader("Content-Disposition", "attachment; filename=MyContacts.xls");

            List<NameValuePair> paramList = new ArrayList<>();
            paramList.add(new BasicNameValuePair("Token", conMan.getToken()));

            post.setEntity(new UrlEncodedFormEntity(paramList));

            HttpResponse resp = client.execute(post);
            HttpEntity entity = resp.getEntity();

            InputStream inStream = entity.getContent();
            FileOutputStream outputStream = new FileOutputStream("MyContacts.xls");

            int bytesRead = -1;
            byte[] buffer = new byte[512];
            while ((bytesRead = inStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }

            outputStream.close();
            inStream.close();
        } catch (IOException ex) {
               log4jLogger.error("IOException Occured", ex);
        }


I hope to get the solution, alternative methods to get this thing done. Please note that I did came across a few solutions on StackOverflow and a few other places but they aren't helpful I have tried them already. Similer examples on site like http://www.mkyong.com/java/how-to-download-file-from-website-java-jsp/, I have tried but without success.


Please Note that I cannot give the code for other files since they are independent of this module. Moreover its a bigger project, so I can't give out any code as of now.



Thank you,
Sincerely,
Psycho_Coder.