How to display Excel, PDf files from Webservice on AEM pages - aem

Question

I'm trying to do the following: The response of a webservice is an excel (a separate call for pdf) file. I need to show this file as a link on the aem-page, and whne users click the link, the browser opens (or downloads) the file.
Use case: On the customer page, there is a section with links to Order History (Excel file), Invoice(PDF file), Products catalog(Excel file). Clicking on each link, makes a call to webservice and fetches the respective file.
how to achieve this?

Answer 1

With help from Scott:
http://help-forums.adobe.com/content/adobeforums/en/experience-manager-forum/adobe-experience-manager.topic.html/forum__xhh5-objective_therespo.html
Here's my solution:
From the UI, submit the action to Sling Servlet
<form name="importFileForm" method="get" action="/services/getData">
<input type="submit" title="Submit" value="Submit" name="bttnAction">
</form>
Your Servlet class
public class TTIGetServlet extends SlingAllMethodsServlet {
#Override
protected void doGet(SlingHttpServletRequest request,SlingHttpServletResponse response) throws ServletException,IOException {
...
...
String serviceurl = <<< your webservice url>>>
HttpClient httpclient = HttpClients.custom().build();
generateFile(serviceurl, httpclient, request, response);
RequestDispatcher dispatcher = request.getRequestDispatcher("/content/ttii/en/importfiletest.html");
dispatcher.forward(request, response);
}
}
Generate File method that pops up the file download on browser
public static void generateFile(String serviceurl,
HttpClient httpclient,
SlingHttpServletRequest httpRequest,
SlingHttpServletResponse httpResponse) throws ClientProtocolException, IOException {
HttpResponse response;
HttpGet httpGet = new HttpGet(serviceURL);
// Makes the call to WebService
response = httpclient.execute(httpGet);
// CORE LOGIC
if (response!=null) {
ContentType contentType = ContentType.getOrDefault(response.getEntity());
String mimeType = contentType.getMimeType();
if (mimeType.equals(MIMETYPE_JSON)) {
// Out of context here...
} else {
// SHOW THE FILE
ServletOutputStream sos = httpResponse.getOutputStream();
httpResponse.setContentType("application/vnd.ms-excel");
httpResponse.setHeader("Content-Disposition", "attachment;filename=test.xls");
BufferedHttpEntity buf = new BufferedHttpEntity(response.getEntity());
InputStream istream = buf.getContent();
sos.write(FileHelper.writeFiles(istream));
sos.flush();
}
}
}