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javaandroidherokuandroid-volleymobile-application

How to upload image file to heroku


I am currently doing android app for plant recognition using machine learning model which is deployed in Heroku. I capture image using camera implemented in my app and I want to send that image into api deployed in heroku, which will then predict the image and send me back the response in a string format which tells us that to which species it belongs to.

public class MainActivity extends AppCompatActivity {
private final int CAMERA_REQ_CODE=100;
private final int GALLERY_REQ_CODE=1000;
ImageView imgCam;

Bitmap img;
String url = "https://medkit.herokuapp.com/predict";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    imgCam=findViewById(R.id.imgCamera);
    Button btnCamera=findViewById(R.id.btnCamera);
    Button btnGallery=findViewById(R.id.btnGallery);
    Button btnPredict=findViewById(R.id.btnPredict);
    TextView result=findViewById(R.id.resultText);


    btnCamera.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent iCamera=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            startActivityForResult(iCamera,CAMERA_REQ_CODE);
        }
    });
    btnGallery.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent iGallery=new Intent(Intent.ACTION_PICK);
            iGallery.setData(MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(iGallery,GALLERY_REQ_CODE);

        }
    });
    btnPredict.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try {
                        JSONObject jsonObject = new JSONObject(response);
                        String data = jsonObject.getString("y_pred_mobile");
                        if (data.equals("1")) {
                            result.setText("Hibiscus");
                        } else if (data.equals("2")) {
                            result.setText("Aloevera");
                        } else if (data.equals("3")) {
                            result.setText("Brahmi");
                        } else if (data.equals("4")) {
                            result.setText("Neem");
                        } else {
                            result.setText("not in the selected species");
                        }


                    } catch (JSONException e) {
                        e.printStackTrace();
                    }


                }
            }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(MainActivity.this, error.getMessage(), Toast.LENGTH_SHORT).show();

                }
            }) {@override
                 protected Map<String,String> getParams(){
                    Map<String,String> params = new HashMap<String,String>();
                    params.put("cgpa",cgpa.getText().toString());
                    params.put("iq",iq.getText().toString());
                    params.put("profile_score",profile_score.getText().toString());

                    return params;

                }

            };
            RequestQueue queue = Volley.newRequestQueue(MainActivity.this);
            queue.add(stringRequest);




        }
    });
}
@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(resultCode==RESULT_OK)
    {
        if(requestCode==CAMERA_REQ_CODE)
        {
            //for camera
            Bitmap img=(Bitmap)(data.getExtras().get("data"));
            imgCam.setImageBitmap(img);

        }
        if(requestCode==GALLERY_REQ_CODE)
        {
            //for Gallery
            imgCam.setImageURI(data.getData());
        }
    }
}

} ` above is my app code. Rest all works fine but i need a code that will put image instead of string for example

@Override
                protected Map<String,String> getParams(){
                    Map<String,String> params = new HashMap<String,String>();
                    params.put("cgpa",cgpa.getText().toString());
                    params.put("iq",iq.getText().toString());
                    params.put("profile_score",profile_score.getText().toString());

                    return params;

this code is to send string as a data , I need a code that can send image as data to the api instead of string like in the above code

Can anyone please help me to fix this ?


Solution

  • I assume that you're trying to upload a bitmap image to your Heroku server. Then the below code sample could help you.

    Create a class VolleyMultipartRequest same as shown below. This class allows MultiPart files to be sent to the server.

    import com.android.volley.AuthFailureError;
    import com.android.volley.NetworkResponse;
    import com.android.volley.ParseError;
    import com.android.volley.Request;
    import com.android.volley.Response;
    import com.android.volley.VolleyError;
    import com.android.volley.toolbox.HttpHeaderParser;
    
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.UnsupportedEncodingException;
    import java.util.Map;
    
    public class VolleyMultipartRequest extends Request<NetworkResponse> {
    
        private final String twoHyphens = "--";
        private final String lineEnd = "\r\n";
        private final String boundary = "APIClient-" + System.currentTimeMillis ();
        private final Response.Listener<NetworkResponse> mListener;
        private final Response.ErrorListener mErrorListener;
    
        public VolleyMultipartRequest ( int method, String url, Response.Listener<NetworkResponse> listener, Response.ErrorListener errorListener ) {
            super ( method, url, errorListener );
            this.mListener = listener;
            this.mErrorListener = errorListener;
        }
    
        @Override
        public Map<String, String> getHeaders () throws AuthFailureError {
            return super.getHeaders ();
        }
    
        @Override
        public String getBodyContentType () {
            return "multipart/form-data;boundary=" + boundary;
        }
    
        @Override
        public byte[] getBody () throws AuthFailureError {
            ByteArrayOutputStream bos = new ByteArrayOutputStream ();
            DataOutputStream dos = new DataOutputStream ( bos );
            try {
                // populate text payload
                Map<String, String> params = getParams ();
                if (params != null && params.size () > 0) {
                    textParse ( dos, params, getParamsEncoding () );
                }
                // populate data byte payload
                Map<String, DataPart> data = getByteData ();
                if (data != null && data.size () > 0) {
                    dataParse ( dos, data );
                }
                // close multipart form data after text and file data
                dos.writeBytes ( twoHyphens + boundary + twoHyphens + lineEnd );
                return bos.toByteArray ();
            } catch (IOException e) {
                e.printStackTrace ();
            }
            return null;
        }
    
        /**
         * Custom method handle data payload.
         *
         * @return Map data part label with data byte
         */
        protected Map<String, DataPart> getByteData () {
            return null;
        }
    
        @Override
        protected Response<NetworkResponse> parseNetworkResponse ( NetworkResponse response ) {
            try {
                return Response.success ( response, HttpHeaderParser.parseCacheHeaders ( response ) );
            } catch (Exception e) {
                return Response.error ( new ParseError ( e ) );
            }
        }
    
        @Override
        protected void deliverResponse ( NetworkResponse response ) {
            mListener.onResponse ( response );
        }
    
        @Override
        public void deliverError ( VolleyError error ) {
            mErrorListener.onErrorResponse ( error );
        }
    
        /**
         * Parse string map into data output stream by key and value.
         *
         * @param dataOutputStream data output stream handle string parsing
         * @param params           string inputs collection
         * @param encoding         encode the inputs, default UTF-8
         * @throws IOException IOException
         */
        private void textParse ( DataOutputStream dataOutputStream, Map<String, String> params, String encoding ) throws IOException {
            try {
                for (Map.Entry<String, String> entry : params.entrySet ()) {
                    buildTextPart ( dataOutputStream, entry.getKey (), entry.getValue () );
                }
            } catch (UnsupportedEncodingException uee) {
                throw new RuntimeException ( "Encoding not supported: " + encoding, uee );
            }
        }
    
        /**
         * Parse data into data output stream.
         *
         * @param dataOutputStream data output stream handle file attachment
         * @param data             loop through data
         * @throws IOException IOException
         */
        private void dataParse ( DataOutputStream dataOutputStream, Map<String, DataPart> data ) throws IOException {
            for (Map.Entry<String, DataPart> entry : data.entrySet ()) {
                buildDataPart ( dataOutputStream, entry.getValue (), entry.getKey () );
            }
        }
    
        /**
         * Write string data into header and data output stream.
         *
         * @param dataOutputStream data output stream handle string parsing
         * @param parameterName    name of input
         * @param parameterValue   value of input
         * @throws IOException IOException
         */
        private void buildTextPart ( DataOutputStream dataOutputStream, String parameterName, String parameterValue ) throws IOException {
            dataOutputStream.writeBytes ( twoHyphens + boundary + lineEnd );
            dataOutputStream.writeBytes ( "Content-Disposition: form-data; name=\"" + parameterName + "\"" + lineEnd );
            dataOutputStream.writeBytes ( lineEnd );
            dataOutputStream.writeBytes ( parameterValue + lineEnd );
        }
    
        /**
         * Write data file into header and data output stream.
         *
         * @param dataOutputStream data output stream handle data parsing
         * @param dataFile         data byte as DataPart from collection
         * @param inputName        name of data input
         * @throws IOException IOException
         */
        private void buildDataPart ( DataOutputStream dataOutputStream, DataPart dataFile, String inputName ) throws IOException {
            dataOutputStream.writeBytes ( twoHyphens + boundary + lineEnd );
            dataOutputStream.writeBytes ( "Content-Disposition: form-data; name=\"" +
                    inputName + "\"; filename=\"" + dataFile.getFileName () + "\"" + lineEnd );
            dataOutputStream.writeBytes ( lineEnd );
            ByteArrayInputStream fileInputStream = new ByteArrayInputStream ( dataFile.getContent () );
            int bytesAvailable = fileInputStream.available ();
            int maxBufferSize = 1024 * 1024;
            int bufferSize = Math.min ( bytesAvailable, maxBufferSize );
            byte[] buffer = new byte[bufferSize];
            int bytesRead = fileInputStream.read ( buffer, 0, bufferSize );
            while (bytesRead > 0) {
                dataOutputStream.write ( buffer, 0, bufferSize );
                bytesAvailable = fileInputStream.available ();
                bufferSize = Math.min ( bytesAvailable, maxBufferSize );
                bytesRead = fileInputStream.read ( buffer, 0, bufferSize );
            }
            dataOutputStream.writeBytes ( lineEnd );
        }
    
        public static class DataPart {
            private final String fileName;
            private final byte[] content;
    
            DataPart ( String name, byte[] data ) {
                fileName = name;
                content = data;
            }
    
            String getFileName () {
                return fileName;
            }
    
            byte[] getContent () {
                return content;
            }
        }
    }
    

    After adding the above class, call the below uploadImage method. Pass the bitmap which you have received from camera or gallery to this method

    /**
     * This method sends bitmap image to backend server
     * 
     * @param bitmap
     */
    public void uploadImage ( final Bitmap bitmap ) {
        VolleyMultipartRequest volleyMultipartRequest = new VolleyMultipartRequest ( Request.Method.POST,
                "YOUR_IMAGE_UPLOAD_URL",
                this::showSuccessMessage,
                this::showErrorMessage
        ) {
            @Override
            protected Map<String, DataPart> getByteData () {
                Map<String, DataPart> params = new HashMap<> ();
                long imageName = System.currentTimeMillis ();
                params.put ( "image", new DataPart ( imageName + ".jpg", getFileDataFromDrawable ( bitmap ) ) );
                return params;
            }
            //Ignore the below override if you're not using any AUTHORIZATION
            @Override
            public Map<String, String> getHeaders () {
                Map<String, String> params = new HashMap<> ();
                params.put ( "authorization", "YOUR AUTH TOKEN" );
                return params;
            }
        };
        volleyMultipartRequest.setRetryPolicy ( new DefaultRetryPolicy (
                100000,
                DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT ) );
        Volley.newRequestQueue ( context ).add ( volleyMultipartRequest );
    }
    
    /**
     * This method is used to display response message
     * 
     * @param response
     */
    private void showSuccessMessage ( NetworkResponse response ) {
        Log.d ( "LOG", "Response from server: " + response.toString () );
    }
    
    /**
     * This method is used to display error message
     * 
     * @param volleyError
     */
    private void showErrorMessage ( VolleyError volleyError ) {
        Log.d ( "LOG", "Response from server: " + volleyError.getMessage () );
    }
    
    /**
     * This method converts bitmap to byte array
     * 
     * @param bitmap
     * @return byte array
     */
    private byte[] getFileDataFromDrawable ( Bitmap bitmap ) {
        ByteArrayOutputStream byteArrayOutputStream = null;
        try {
            byteArrayOutputStream = new ByteArrayOutputStream ();
            bitmap.compress ( Bitmap.CompressFormat.JPEG, 100, byteArrayOutputStream );
        } catch (Exception ignored) {
    
        } finally {
            if (byteArrayOutputStream != null) {
                try {
                    byteArrayOutputStream.close ();
                } catch (IOException ignore) {
                }
            }
        }
        return (byteArrayOutputStream != null ? byteArrayOutputStream.toByteArray () : null);
    }
    

    This is the working code which I am using. Hope the above code snippet helps you. Please let me know if I have missed any necessary code snippets in this answer. I will try to update those