Android Upload multiple file using Retrofit as multipart


Example

Once you have setup the Retrofit environment in your project, you can use the following example that demonstrates how to upload multiple files using Retrofit:

private void mulipleFileUploadFile(Uri[] fileUri) {
    OkHttpClient okHttpClient = new OkHttpClient();
    OkHttpClient clientWith30sTimeout = okHttpClient.newBuilder()
            .readTimeout(30, TimeUnit.SECONDS)
            .build();

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(API_URL_BASE)
            .addConverterFactory(new MultiPartConverter())
            .client(clientWith30sTimeout)
            .build();

    WebAPIService service = retrofit.create(WebAPIService.class); //here is the interface which you have created for the call service
    Map<String, okhttp3.RequestBody> maps = new HashMap<>();

    if (fileUri!=null && fileUri.length>0) {
        for (int i = 0; i < fileUri.length; i++) {
            String filePath = getRealPathFromUri(fileUri[i]);
            File file1 = new File(filePath);

            if (filePath != null && filePath.length() > 0) {
                if (file1.exists()) {
                    okhttp3.RequestBody requestFile = okhttp3.RequestBody.create(okhttp3.MediaType.parse("multipart/form-data"), file1);
                    String filename = "imagePath" + i; //key for upload file like : imagePath0
                    maps.put(filename + "\"; filename=\"" + file1.getName(), requestFile);
                }
            }
        }
    }

    String descriptionString = " string request";//
    //hear is the your json request
    Call<String> call = service.postFile(maps, descriptionString);
    call.enqueue(new Callback<String>() {
        @Override
        public void onResponse(Call<String> call,
                               Response<String> response) {
            Log.i(LOG_TAG, "success");
            Log.d("body==>", response.body().toString() + "");
            Log.d("isSuccessful==>", response.isSuccessful() + "");
            Log.d("message==>", response.message() + "");
            Log.d("raw==>", response.raw().toString() + "");
            Log.d("raw().networkResponse()", response.raw().networkResponse().toString() + "");
        }

        @Override
        public void onFailure(Call<String> call, Throwable t) {
            Log.e(LOG_TAG, t.getMessage());
        }
    });
}
    
public String getRealPathFromUri(final Uri uri) { // function for file path from uri,
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT && DocumentsContract.isDocumentUri(mContext, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            if ("primary".equalsIgnoreCase(type)) {
                return Environment.getExternalStorageDirectory() + "/" + split[1];
            }
        }
        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {

            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

            return getDataColumn(mContext, contentUri, null, null);
        }
        // MediaProvider
        else if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            Uri contentUri = null;
            if ("image".equals(type)) {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            } else if ("video".equals(type)) {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            } else if ("audio".equals(type)) {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            }

            final String selection = "_id=?";
            final String[] selectionArgs = new String[]{
                    split[1]
            };

            return getDataColumn(mContext, contentUri, selection, selectionArgs);
        }
    }
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {

        // Return the remote address
        if (isGooglePhotosUri(uri))
            return uri.getLastPathSegment();

        return getDataColumn(mContext, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

Following is the interface

public interface WebAPIService {
    @Multipart
    @POST("main.php")
    Call<String> postFile(@PartMap Map<String,RequestBody> Files, @Part("json") String description);
}