How to download image using Retrofit or Picasso via HTTP POST method

sajjad Yosefi :

I have a HTTP post request, it takes a JSON with the following content as request body:

{
  "UserName":"ApiService", 
  "Password":"BandarAndroid",
  "AndroidId":"15df3b3a90XXXXX",
  "ContentId":"704",
  "frame":"1"
}

After requesting to the server, I get only one image in response(Instead of anything (like JSON)). The appropriate image is created on request and has no web address. my service Address is :

http://xyz.website.com/api/DownloadFileForAndroid

and my response header is :

cache-control →no-cache
content-length →29837
content-type →image/png
date →Mon, 09 Sep 2019 08:42:23 GMT
expires →-1
pragma →no-cache
server →Microsoft-IIS/8.5
x-aspnet-version →4.0.30319
x-powered-by →ASP.NET

I don't know whether to use retrofit or Picasso to get this photo,

in Picasso: I can't send the amount of JSON in the request body.

in retrofit: I can't get the photo without the url (Address to point to the photo like www.site.com/a.jpg)

Roaim :

As you requested, I am converting my previous solution (Kotlin) to Java

Example 1: Picasso

public void loadImageWithPicasso(ImageView imageView) {
    Picasso.Builder builder = new Picasso.Builder(imageView.getContext());
    RequestCreator picassoImageLoader = createPicassoLoader(
            builder,
            ImageRequest.DEFAULT_JSON_BODY,
            "http://shop.atiafkar.ir/api/DownloadFileForAndroid"
    );
    picassoImageLoader.into(imageView);
}

public RequestCreator createPicassoLoader(Picasso.Builder builder, String body, String url) {
    return builder.downloader(new OkHttp3Downloader(createPicassoCallFactory(body)))
            .build()
            .load(url);
}

private okhttp3.Call.Factory createPicassoCallFactory(String jsonBody) {
    final OkHttpClient okHttpClient = new OkHttpClient.Builder()
            .build();
    final RequestBody requestBody = RequestBody.create(MediaType.parse("application/json"), jsonBody);
    return new okhttp3.Call.Factory() {
        @Override
        public okhttp3.Call newCall(Request request) {
            Request.Builder builder = request.newBuilder();
            builder.post(requestBody);
            builder.addHeader("Content-Type", "application/json");
            return okHttpClient.newCall(builder.build());
        }
    };
}

---

Example 2: Retrofit

public void loadImageWithRetrofit(ImageView imageView) {
        final RetrofitImageLoader imageLoader = new RetrofitImageLoader(imageView);
        RemoteApi api = RemoteApi.Factory.create();

        api.getImage(ImageRequest.DEFAULT_BODY).enqueue(new Callback<ResponseBody>() {
            @Override
            public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                ResponseBody body = response.body();
                if (response.isSuccessful() && body != null) {
                    imageLoader.execute(body.byteStream());
                } else {
                    Log.d(TAG, "Retrofit onResponse(): CODE = [" + response.code() + "], MESSAGE = [" + response.message() + "]");
                }
            }

            @Override
            public void onFailure(Call<ResponseBody> call, Throwable t) {
                Log.d(TAG, "Retrofit onFailure(): t = [" + t + "]");
            }
        });
}

RetrofitImageLoader class

public class RetrofitImageLoader extends AsyncTask<InputStream, Integer, Bitmap> {
        private ImageView imageView;

        private RetrofitImageLoader(ImageView imageView) {
            this.imageView = imageView;
        }

        @Override
        protected Bitmap doInBackground(InputStream... inputStreams) {
            return BitmapFactory.decodeStream(inputStreams[0]);
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            super.onPostExecute(bitmap);
            imageView.setImageBitmap(bitmap);
        }
}

RemoteApi interface

public interface RemoteApi {
    @Streaming  // Important
    @POST("/api/DownloadFileForAndroid")
    Call<ResponseBody> getImage(@Body ImageRequest body);

    class Factory {
        private static RemoteApi mInstance;

        public static RemoteApi create() {
            if (mInstance == null) {
                mInstance = new Retrofit.Builder()
                        .addConverterFactory(GsonConverterFactory.create())
                        .baseUrl("http://shop.atiafkar.ir")
                        .build()
                        .create(RemoteApi.class);
            }
            return mInstance;
        }
    }
}

ImageRequest model class

public class ImageRequest{
    public static final ImageRequest DEFAULT_BODY;
    public static final String DEFAULT_JSON_BODY;

    static {
        DEFAULT_BODY = new ImageRequest();
        DEFAULT_BODY.setAndroidId("15df3b3a90dc5688");
        DEFAULT_BODY.setContentId("704");
        DEFAULT_BODY.setFrame("1");
        DEFAULT_BODY.setPassword("BandarAndroid");
        DEFAULT_BODY.setUserName("ApiService");

        DEFAULT_JSON_BODY = new Gson().toJson(DEFAULT_BODY, ImageRequest.class);
    }

    @SerializedName("UserName")
    private String userName;
    @SerializedName("ContentId")
    private String contentId;
    @SerializedName("AndroidId")
    private String androidId;
    @SerializedName("Password")
    private String password;
    @SerializedName("frame")
    private String frame;

    public void setUserName(String userName){
        this.userName = userName;
    }
    public void setContentId(String contentId){
        this.contentId = contentId;
    }
    public void setAndroidId(String androidId){
        this.androidId = androidId;
    }
    public void setPassword(String password){
        this.password = password;
    }
    public void setFrame(String frame){
        this.frame = frame;
    }
}