How to send body text field along with files in Android POST multipart form data

Question

I'm trying to post an image along with some text fields to a server. I'm following the following code to POST the file to server, and its working fine. But I'm not able to figure out where to send the text field.

public class TaskPostData extends AsyncTask<Void, Void, Void> {
    private final ProgressDialog dialog = new ProgressDialog(MainActivity.this);

    protected void onPreExecute() {
        this.dialog.setMessage("Loading...");
        this.dialog.setCancelable(false);
        this.dialog.show();
    }

    @Override
    protected Void doInBackground(Void... arg0) {
        HttpURLConnection conn = null;
        DataOutputStream dos = null;
        DataInputStream inStream = null;
        String existingFileName = file_path;
        String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";
        int bytesRead, bytesAvailable, bufferSize;
        byte[] buffer;
        int maxBufferSize = 1 * 1024 * 1024;
        String urlString = "http://my/post/url";
        try {
            InputStream fileInputStream = getContentResolver().openInputStream(selectedImage);
            URL url = new URL(urlString);
            conn = (HttpURLConnection) url.openConnection();
            conn.setDoInput(true);
            conn.setDoOutput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
            dos = new DataOutputStream(conn.getOutputStream());
            dos.writeBytes(twoHyphens + boundary + lineEnd);

            dos.writeBytes("Content-Disposition: form-data; name=\"image\";filename=\"" + upload_file_name + "\"" + lineEnd); // uploaded_file_name is the Name of the File to be uploaded
            dos.writeBytes(lineEnd);
            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            while (bytesRead > 0) {
                dos.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
            }
            dos.writeBytes(lineEnd);
            dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);
            fileInputStream.close();
            dos.flush();
            dos.close();
        } catch (MalformedURLException ex) {
            Log.e("Debug", "error: " + ex.getMessage(), ex);
        } catch (IOException ioe) {
            Log.e("Debug", "error: " + ioe.getMessage(), ioe);
        }

        try {
            inStream = new DataInputStream(conn.getInputStream());
            String str;
            while ((str = inStream.readLine()) != null) {
                Log.e("Debug", "Server Response " + str);
                reponse_data = str;
            }
            inStream.close();
        } catch (IOException ioex) {
            Log.e("Debug", "error: " + ioex.getMessage(), ioex);
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {

        if (this.dialog.isShowing()) {
            this.dialog.dismiss();
        }
    }
}

Every part of a multipart is in between two boundary lines. So add a new Content-Disposition line also. — greenapps, Oct 08 '15 at 07:12
@greenapps: please give a small example code. I've 18 fields to be sent along with one image. — Krishanu Dey, Oct 08 '15 at 07:17
Look at the answer here http://stackoverflow.com/questions/17320886/httpclient-post-with-content-disposition to see how your output should look like. Every parameter with it's value goes between boundaries. — greenapps, Oct 08 '15 at 07:52
@greenapps: Thanks a lot. Finally made it work. your last comment was really helped. — Krishanu Dey, Oct 08 '15 at 08:09
@downvoter: Please explain the down vote. As without explanation of down vote, it's worth less. — Krishanu Dey, Oct 08 '15 at 08:11

Tixeon · Answer 1 · 2015-10-08T07:10:35.043

0

private static final String POST_PARAMS = "userName=Pankaj";

here is how i would add

dos.write(POST_PARAMS.getBytes());

edited Oct 08 '15 at 07:10

answered Oct 08 '15 at 07:09

Tixeon

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But where to add those lines? – Krishanu Dey Oct 08 '15 at 07:10
Good question. Sanny's solution will only work without an image. – greenapps Oct 08 '15 at 07:13

How to send body text field along with files in Android POST multipart form data

1 Answers1