如何在AEM页面上显示来自Webservice的Excel、PDf文件

我尝试做以下工作：Web服务的响应是一个excel（对pdf的单独调用）文件。我需要在aem页面上将此文件显示为链接，当用户单击该链接时，浏览器将打开（或下载）该文件

用例：在客户页面上，有一个部分包含到订单历史记录（Excel文件）、发票（PDF文件）、产品目录（Excel文件）的链接。单击每个链接，调用webservice并获取相应的文件

如何实现这一点？

在Scott的帮助下：

以下是我的解决方案：

从UI中，将操作提交到Servlet

<form name="importFileForm" method="get" action="/services/getData">
<input type="submit" title="Submit" value="Submit" name="bttnAction">
</form>

}

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);        
  }
}

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();     
    }
}