Retrofit API to retrieve a png image

Question

Hi I am new to Retrofit framework for Android. I could get JSON responses from REST services using it but I don\'t know how to download a png using retrofit. I am trying to

Answer 1

I hope following code will help you:

Include following function inside MainActivity.java:

void getRetrofitImage() {
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(url)
            .addConverterFactory(GsonConverterFactory.create())
            .build();

    RetrofitImageAPI service = retrofit.create(RetrofitImageAPI.class);

    Call<ResponseBody> call = service.getImageDetails();

    call.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Response<ResponseBody> response, Retrofit retrofit) {

            try {

                Log.d("onResponse", "Response came from server");

                boolean FileDownloaded = DownloadImage(response.body());

                Log.d("onResponse", "Image is downloaded and saved ? " + FileDownloaded);

            } catch (Exception e) {
                Log.d("onResponse", "There is an error");
                e.printStackTrace();
            }

        }

        @Override
        public void onFailure(Throwable t) {
            Log.d("onFailure", t.toString());
        }
    });
}

Following is the file handling code for image:

private boolean DownloadImage(ResponseBody body) {

        try {
            Log.d("DownloadImage", "Reading and writing file");
            InputStream in = null;
            FileOutputStream out = null;

            try {
                in = body.byteStream();
                out = new FileOutputStream(getExternalFilesDir(null) + File.separator + "AndroidTutorialPoint.jpg");
                int c;

                while ((c = in.read()) != -1) {
                    out.write(c);
                }
            }
            catch (IOException e) {
                Log.d("DownloadImage",e.toString());
                return false;
            }
            finally {
                if (in != null) {
                    in.close();
                }
                if (out != null) {
                    out.close();
                }
            }

            int width, height;
            ImageView image = (ImageView) findViewById(R.id.imageViewId);
            Bitmap bMap = BitmapFactory.decodeFile(getExternalFilesDir(null) + File.separator + "AndroidTutorialPoint.jpg");
            width = 2*bMap.getWidth();
            height = 6*bMap.getHeight();
            Bitmap bMap2 = Bitmap.createScaledBitmap(bMap, width, height, false);
            image.setImageBitmap(bMap2);

            return true;

        } catch (IOException e) {
            Log.d("DownloadImage",e.toString());
            return false;
        }
    }

This is done using Android Retrofit 2.0. I hope it helped you.

Source: Image Download using Retrofit 2.0

Answer 2

Retrofit is a REST library, you can use Retrofit only to get image URL but for displaying Image you should use Picasso: http://square.github.io/picasso/