android - POST a file with other form data using HttpURLConnection

Question

Im trying to POST a file to an API of mine along with other parameters.

Eg. POST /media with the parameters

filename = 'test.png'

file = -the-actual-file-

I can do this successfully with Postman (using form-data), so the api side of things are fine.

Here is my android code using HttpURLConnection:

nameValuePairs.add(new BasicNameValuePair("filename", "test.png"));

URL object = new URL(url);
HttpURLConnection connection = (HttpURLConnection) object.openConnection();
connection.setReadTimeout(60 * 1000);
connection.setConnectTimeout(60 * 1000);
String auth = username+":"+password;
    byte[] data = auth.getBytes();
    String encodeAuth = "Basic " + Base64.encodeToString(data, Base64.DEFAULT);
    connection.setDoInput(true);
    connection.setDoOutput(true);
    connection.setUseCaches(false);
    connection.setRequestProperty("Authorization", encodeAuth);
    connection.setRequestProperty("Accept", ACCEPT);
    connection.setRequestMethod("POST");
    connection.setRequestProperty("ENCTYPE", "multipart/form-data");
    connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
    dataOutputStream = new DataOutputStream(connection.getOutputStream());
    writer = new BufferedWriter(new OutputStreamWriter(dataOutputStream, "UTF-8"));
    writer.write(getQuery(nameValuePairs));

     writer.write("&file=" + "image.jpg");
     writer.write
     File file = getFile(item);
     if (file == null) {
      Log.e("uploadFile", "Source File not exist " );
     } else {
      addFilePart("file", file);
     }
    }
    writer.flush();
    writer.close();
    dataOutputStream.close();


    connection.connect();

Answer 1

Android multipart upload.

public String multipartRequest(String urlTo, Map<String, String> parmas, String filepath, String filefield, String fileMimeType) throws CustomException {
        HttpURLConnection connection = null;
        DataOutputStream outputStream = null;
        InputStream inputStream = null;

        String twoHyphens = "--";
        String boundary = "*****" + Long.toString(System.currentTimeMillis()) + "*****";
        String lineEnd = "
";

        String result = "";

        int bytesRead, bytesAvailable, bufferSize;
        byte[] buffer;
        int maxBufferSize = 1 * 1024 * 1024;

        String[] q = filepath.split("/");
        int idx = q.length - 1;

        try {
            File file = new File(filepath);
            FileInputStream fileInputStream = new FileInputStream(file);

            URL url = new URL(urlTo);
            connection = (HttpURLConnection) url.openConnection();

            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setUseCaches(false);

            connection.setRequestMethod("POST");
            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setRequestProperty("User-Agent", "Android Multipart HTTP Client 1.0");
            connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);

            outputStream = new DataOutputStream(connection.getOutputStream());
            outputStream.writeBytes(twoHyphens + boundary + lineEnd);
            outputStream.writeBytes("Content-Disposition: form-data; name="" + filefield + ""; filename="" + q[idx] + """ + lineEnd);
            outputStream.writeBytes("Content-Type: " + fileMimeType + lineEnd);
            outputStream.writeBytes("Content-Transfer-Encoding: binary" + lineEnd);

            outputStream.writeBytes(lineEnd);

            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];

            bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            while (bytesRead > 0) {
                outputStream.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            }

            outputStream.writeBytes(lineEnd);

            // Upload POST Data
            Iterator<String> keys = parmas.keySet().iterator();
            while (keys.hasNext()) {
                String key = keys.next();
                String value = parmas.get(key);

                outputStream.writeBytes(twoHyphens + boundary + lineEnd);
                outputStream.writeBytes("Content-Disposition: form-data; name="" + key + """ + lineEnd);
                outputStream.writeBytes("Content-Type: text/plain" + lineEnd);
                outputStream.writeBytes(lineEnd);
                outputStream.writeBytes(value);
                outputStream.writeBytes(lineEnd);
            }

            outputStream.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);


            if (200 != connection.getResponseCode()) {
                throw new CustomException("Failed to upload code:" + connection.getResponseCode() + " " + connection.getResponseMessage());
            }

            inputStream = connection.getInputStream();

            result = this.convertStreamToString(inputStream);

            fileInputStream.close();
            inputStream.close();
            outputStream.flush();
            outputStream.close();

            return result;
        } catch (Exception e) {
            logger.error(e);
            throw new CustomException(e);
        }

    }

    private String convertStreamToString(InputStream is) {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }

Calling code:

//setup params
Map<String, String> params = new HashMap<String, String>(2);
        params.put("foo", hash);
        params.put("bar", caption);

String result = multipartRequest(URL_UPLOAD_VIDEO, params, pathToVideoFile, "video", "video/mp4");
//next parse result string

Ref Link https://stackoverflow.com/a/26145565/1143026