How to save multiple image files in the SD card using picasso?

    public class MainActivity extends AppCompatActivity {

        private ImageView mImageView;
        private String mURL = "http://www.allindiaflorist.com/imgs/arrangemen4.jpg";
        private String urls = "http://api.androidhive.info/images/sample.jpg";
        private String[] urlArray = {mURL, urls};

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            mImageView = (ImageView) findViewById(R.id.imageViewID);

        }

        @Override
        protected void onResume() {
            super.onResume();

            Picasso.with(getApplicationContext()).load(mURL).into(mImageView);

            for (int i=0; i<urlArray.length; i++) {
                Picasso.with(getApplicationContext()).load(urlArray[i]).into(target);

            }

        }

        private Target target = new Target() {
            @Override
            public void onBitmapLoaded(final Bitmap bitmap, Picasso.LoadedFrom from) {

                new Thread(new Runnable() {
                    @Override
                    public void run() {

                        File sd = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
                        File folder = new File(sd, "/Picasso/");
                        if (!folder.exists()) {
                            if (!folder.mkdir()) {
                                Log.e("ERROR", "Cannot create a directory!");
                            } else {
                                folder.mkdir();
                            }
                        }

                        File[] fileName = {new File(folder, "one.jpg"), new File(folder, "two.jpg")};

                        for (int i=0; i<fileName.length; i++) {

                            if (!fileName[i].exists()) {
                                try {
                                    fileName[i].createNewFile();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            } else {

                                try {
                                    FileOutputStream outputStream = new FileOutputStream(String.valueOf(fileName[i]));
                                    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
                                    outputStream.close();

                                } catch (FileNotFoundException e) {
                                    e.printStackTrace();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }
                            }

                        }

                    }
                }).start();

            }

            @Override
            public void onBitmapFailed(Drawable errorDrawable) {

            }

            @Override
            public void onPrepareLoad(Drawable placeHolderDrawable) {

            }
        };

    }