simple HttpURLConnection POST file multipart/form-data from android to google blobstore

Question

I have very little idea how html works.What i want to do is exactly similar to the following but on android

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Answer 1

I am using HttpURLConnection to achieve this.

Create one Multipart custom class ::

public class MultipartUtility {
    private final String boundary;
    private static final String LINE_FEED = "\r\n";
    private HttpURLConnection httpConn;
    private String charset;
    private OutputStream outputStream;
    private PrintWriter writer;

    /**
     * This constructor initializes a new HTTP POST request with content type
     * is set to multipart/form-data
     *
     * @param requestURL
     * @param charset
     * @throws IOException
     */
    public MultipartUtility(String requestURL, String charset)
            throws IOException {
        this.charset = charset;

        // creates a unique boundary based on time stamp
        boundary = "===" + System.currentTimeMillis() + "===";
        URL url = new URL(requestURL);
        httpConn = (HttpURLConnection) url.openConnection();
        httpConn.setUseCaches(false);
        httpConn.setDoOutput(true);    // indicates POST method
        httpConn.setDoInput(true);
        httpConn.setRequestProperty("Content-Type",
                "multipart/form-data; boundary=" + boundary);
        outputStream = httpConn.getOutputStream();
        writer = new PrintWriter(new OutputStreamWriter(outputStream, charset),
                true);
    }

    /**
     * Adds a form field to the request
     *
     * @param name  field name
     * @param value field value
     */
    public void addFormField(String name, String value) {
        writer.append("--" + boundary).append(LINE_FEED);
        writer.append("Content-Disposition: form-data; name=\"" + name + "\"")
                .append(LINE_FEED);
        writer.append("Content-Type: text/plain; charset=" + charset).append(
                LINE_FEED);
        writer.append(LINE_FEED);
        writer.append(value).append(LINE_FEED);
        writer.flush();
    }

    /**
     * Adds a upload file section to the request
     *
     * @param fieldName  name attribute in <input type="file" name="..." />
     * @param uploadFile a File to be uploaded
     * @throws IOException
     */
    public void addFilePart(String fieldName, File uploadFile)
            throws IOException {
        String fileName = uploadFile.getName();
        writer.append("--" + boundary).append(LINE_FEED);
        writer.append(
                "Content-Disposition: form-data; name=\"" + fieldName
                        + "\"; filename=\"" + fileName + "\"")
                .append(LINE_FEED);
        writer.append(
                "Content-Type: "
                        + URLConnection.guessContentTypeFromName(fileName))
                .append(LINE_FEED);
        writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
        writer.append(LINE_FEED);
        writer.flush();

        FileInputStream inputStream = new FileInputStream(uploadFile);
        byte[] buffer = new byte[4096];
        int bytesRead = -1;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }
        outputStream.flush();
        inputStream.close();
        writer.append(LINE_FEED);
        writer.flush();
    }

    /**
     * Adds a header field to the request.
     *
     * @param name  - name of the header field
     * @param value - value of the header field
     */
    public void addHeaderField(String name, String value) {
        writer.append(name + ": " + value).append(LINE_FEED);
        writer.flush();
    }

    /**
     * Completes the request and receives response from the server.
     *
     * @return a list of Strings as response in case the server returned
     * status OK, otherwise an exception is thrown.
     * @throws IOException
     */
    public List<String> finish() throws IOException {
        List<String> response = new ArrayList<String>();
        writer.append(LINE_FEED).flush();
        writer.append("--" + boundary + "--").append(LINE_FEED);
        writer.close();

        // checks server's status code first
        int status = httpConn.getResponseCode();
        if (status == HttpURLConnection.HTTP_OK) {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    httpConn.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                response.add(line);
            }
            reader.close();
            httpConn.disconnect();
        } else {
            throw new IOException("Server returned non-OK status: " + status);
        }
        return response;
    }
}

Use it (async way) ::

    MultipartUtility multipart = new MultipartUtility(requestURL, charset);

    // In your case you are not adding form data so ignore this
                /*This is to add parameter values */
                for (int i = 0; i < myFormDataArray.size(); i++) {
                    multipart.addFormField(myFormDataArray.get(i).getParamName(),
                            myFormDataArray.get(i).getParamValue());
                }


//add your file here.
                /*This is to add file content*/
                for (int i = 0; i < myFileArray.size(); i++) {
                    multipart.addFilePart(myFileArray.getParamName(),
                            new File(myFileArray.getFileName()));
                }

                List<String> response = multipart.finish();
                Debug.e(TAG, "SERVER REPLIED:");
                for (String line : response) {
                    Debug.e(TAG, "Upload Files Response:::" + line);
// get your server response here.
                    responseString = line;
                }

Answer 2

use okhttp and use following snippet (taken from recipes)

adjust the header values according to what your server expects.

private static final String IMGUR_CLIENT_ID = "...";
private static final MediaType MEDIA_TYPE_PNG = MediaType.parse("image/png");

private final OkHttpClient client = new OkHttpClient();

public void run() throws Exception {
// Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
    RequestBody requestBody = new MultipartBuilder()
    .type(MultipartBuilder.FORM)
    .addPart(
        Headers.of("Content-Disposition", "form-data; name=\"title\""),
        RequestBody.create(null, "Square Logo"))
    .addPart(
        Headers.of("Content-Disposition", "form-data; name=\"image\""),
        RequestBody.create(MEDIA_TYPE_PNG, new File("website/static/logo-square.png")))
    .build();

Request request = new Request.Builder()
    .header("Authorization", "Client-ID " + IMGUR_CLIENT_ID)
    .url("https://api.imgur.com/3/image")
    .post(requestBody)
    .build();

Response response = client.newCall(request).execute();
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

System.out.println(response.body().string());
}

Answer 3

As alternative you can use Retrofit.

You can specify a call like this:

@Multipart
@POST("/user/photo")
Call<User> updateUser(@Part("photo") RequestBody photo, @Part("description") RequestBody description);

then create it like this:

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.github.com")
    .build();
GitHubService service = retrofit.create(GitHubService.class);

and finally execute it like this:

service.updateUser(Photo, description).enqueue() --> asynchronous

service.updateUser(Photo, description).execute() --> synchronous

See the documentation here

Answer 4

Volley is a good http library for multipart data. AndroidMultiPartEntity class is for progress listener.

    public class AndroidMultiPartEntity extends MultipartEntity

    {

    private final ProgressListener listener;

    public AndroidMultiPartEntity(final ProgressListener listener) {
    super();
    this.listener = listener;
    }

    public AndroidMultiPartEntity(final HttpMultipartMode mode, final ProgressListener listener) {
    super(mode);
    this.listener = listener;
    }

    public AndroidMultiPartEntity(HttpMultipartMode mode, final String boundary,
    final Charset charset, final ProgressListener listener) {
    super(mode, boundary, charset);
    this.listener = listener;
    }

    @Override
    public void writeTo(final OutputStream outstream) throws IOException {
    super.writeTo(new CountingOutputStream(outstream, this.listener));
    }

    public static interface ProgressListener {
    void transferred(long num);
    }

    public static class CountingOutputStream extends FilterOutputStream {

    private final ProgressListener listener;
    private long transferred;

    public CountingOutputStream(final OutputStream out,
                                final ProgressListener listener) {
        super(out);
        this.listener = listener;
        this.transferred = 0;
    }

    public void write(byte[] b, int off, int len) throws IOException {
        out.write(b, off, len);
        this.transferred += len;
        this.listener.transferred(this.transferred);
    }

    public void write(int b) throws IOException {
        out.write(b);
        this.transferred++;
        this.listener.transferred(this.transferred);
    }
    }
    }

    Call the Async task like this
    new UploadFileToServer().execute();


    The Call method:
    private class UploadFileToServer extends AsyncTask<Void, Integer, String> {
    @Override
    protected void onPreExecute() {

        super.onPreExecute();
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {

    }

    @Override
    protected String doInBackground(Void... params) {

        return uploadFile();

    }

    private String uploadFile() {

        String responseString = null;

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(Config.Seeker_Image_Upload);

        try {
            AndroidMultiPartEntity entity = new AndroidMultiPartEntity(new AndroidMultiPartEntity.ProgressListener() {

                @Override
                public void transferred(long num) {
                    publishProgress((int) ((num / (float) totalSize) * 100));
                }
            });

            File sourceFile = new File(Path);

            // Adding file data to http body
            entity.addPart("logo", new FileBody(sourceFile));

            // Extra parameters if you want to pass to server
            //entity.addPart("website", new StringBody("www.androidhive.info"));

            // String emailaddress = UserActivity.emailaddress;

            /*preferences = SeekerProfile.this.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
            email_address = preferences.getString("EMAILADDRESS", "");*/
            entity.addPart("EMAILADDRESS", new StringBody(email_address));
            entity.addPart("OPER", new StringBody(Operation_recruiter_logo_upload));

            totalSize = entity.getContentLength();
            httppost.setEntity(entity);

            // Making server call
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity r_entity = response.getEntity();

            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode == 200) {
                // Server response
                responseString = EntityUtils.toString(r_entity);
            } else {
                responseString = "Error occurred! Http Status Code: " + statusCode;
            }

        } catch (ClientProtocolException e) {
            responseString = e.toString();
        } catch (IOException e) {
            responseString = e.toString();
        }

        return responseString;

        }

        @Override
        protected void onPostExecute(String result) {
        //Log.e(TAG, "Response from server: " + result);
        enter code here
        }

    }