title: HttpClient Post with progress and MultipartEntityBuilder
body: <p>I try to implement an progress while uploading an file with <code>HttpClient</code> 4.3.3 and <code>MultipartEntityBuilder</code></p>
  
  <p>So actually i execute a post request with the following code</p>
  
  <pre><code>HttpClientBuilder builder = HttpClientBuilder.create();
  HttpClient httpClient = builder.build();
  
  HttpPost httpPost = new HttpPost(uploadUrl);
  
  MultipartEntityBuilder entityBuilder = MultipartEntityBuilder.create();
  entityBuilder.addPart("filea", new FileBody(filea));
  entityBuilder.addPart("fileb", new FileBody(fileb));
  
  final HttpEntity entity = entityBuilder.build();
  httpPost.setEntity(entity);
  
  HttpResponse response = httpClient.execute(httpPost);
  </code></pre>
  
  <p>Any idea how to get the actual progress from the upload? I searched a lot - but the examples are for android and not plain java or an older version of <code>HttpClient</code> and didn't work for me...</p>