Microsoft Cognitive Services - Bing Speech to Text with JAVA - curl to http request

Question

i want to code a java http request for posting audio file (wav) for speech to text transformation. I´m quite new to http requests, and could not find any useful hints how to achieve that. In https://www.microsoft.com/cognitive-services/en-us/Speech-api/documentation/GetStarted/GetStarted-cURL I was able to get token (Step 1 in url), but now I am struggeling with step 2. Can someone help or even provide java code for step 2 (post wav file to cognitive services).

CURL Request given:

curl -v -X POST "https://speech.platform.bing.com/recognize? scenarios=smd&appid=D4D52672-91D7-4C74-8AD8- 42B1D98141A5&locale=your_locale&device.os=your_device_os&version=3.0&format=json&instanceid=your_instance_id&requestid=your_request_id" -H 'Authorization: Bearer your_access_token' -H 'Content-type: audio/wav; codec="audio/pcm"; samplerate=16000' --data-binary @your_wave_file

My Java HTTP code so far (Using Apache):

    HttpClient client = HttpClientBuilder.create().build();
    String url = "https://speech.platform.bing.com/recognize";

    String appId = "D4D52672-91D7-4C74-8AD8-42B1D98141A5"; //Always use this. See Docu
    String token = "12345"; // received from step 1 (see MS documentation)
    String locale = "de-DE";
    String deviceOS = "Windows";
    String version = "3.0"; 
    String format = "json"; 
    String instanceid = UUID.randomUUID().toString();
    String scenarios = "smd";

    // setting up post parameters
    Map<String, String> postParameters = new HashMap<>();
    postParameters.put("scenarios", scenarios);
    postParameters.put("appid", appId);
    postParameters.put("locale", locale);
    postParameters.put("device.os", deviceOS);

    postParameters.put("format", format);
    postParameters.put("instanceid", instanceid);
    postParameters.put("requestid", instanceid);
    postParameters.put("version", version);

    // setting up HttpPost
    HttpPost httpPost = new HttpPost(url);

    // PARAMETERS
    List<NameValuePair> qparams = new ArrayList<>();
    for (Map.Entry<String, String> s : postParameters.entrySet()) {
        qparams.add(new BasicNameValuePair(s.getKey(), s.getValue()));
    }
    httpPost.setEntity(new UrlEncodedFormEntity(qparams));
    // HEADERS
    String wavFile = "C:\\Folder\\AudioData.wav";

    Map<String, String> postHeaders = new HashMap<>();
    postHeaders.put("Authorization", "Bearer " + token);
    postHeaders.put("Content-Type", "audio/wav; codec=\"audio/pcm\"; samplerate=16000");


    for (Map.Entry<String, String> entry : postHeaders.entrySet()) {
        httpPost.setHeader(entry.getKey(), entry.getValue());
    }

    // WAV FILE
    File file = new File(wavFile);
    FileBody bin = new FileBody(file, ContentType.DEFAULT_BINARY);
    MultipartEntityBuilder builder = MultipartEntityBuilder.create();
    builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
    builder.addPart("bin", bin);

    HttpEntity reqEntity = builder.build();
    httpPost.setEntity(reqEntity);

    // RESPONSE
    HttpResponse response = client.execute(httpPost);

    int responseCode = response.getStatusLine().getStatusCode();

    System.out.println("\nSending 'POST' request to URL : " + url);
    System.out.println("Response Code : " + responseCode);

    BufferedReader rd = new BufferedReader(
            new InputStreamReader(response.getEntity().getContent()));

    StringBuilder result = new StringBuilder();
    String line = "";
    while ((line = rd.readLine()) != null) {
        result.append(line);
    }
    System.out.println(result.toString());

My Response code is 200, but my response.getEntity().getContent() is empty. I expect a JSON there.

btw: if i fire this up with curl (with set parameters of course) it works, and I get a JSON back with recognized speech to text.

Can you help me with that?

Nycon