public void imageList() {
    File imagePathForImage = new File(Environment.getExternalStorageDirectory());
    imageList = imageReader(imagePathForImage);
    if (imageList.size() != 0) {
        gallery.setAdapter(new imageAdapater());
        gallery.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                Intent openImage = new Intent(getActivity(), FullImageActivity.class);
                openImage.putExtra("Img :", imageList.get(i).toString());
                startActivity(openImage);
            }
        });
    } else {
        Toast.makeText(getActivity(), "No image Found", Toast.LENGTH_SHORT).show();
    }
}
public void imageNameList() {
    imageNameList = new ArrayList<String>();
    File imagePathForName = new File(Environment.getExternalStorageDirectory());
    Cursor cursor = getContext().getContentResolver().query(Uri.fromFile(imagePathForName), null, null, null, null);
    if (cursor == null) {
        Toast.makeText(getActivity(), "No Image File Found", Toast.LENGTH_SHORT).show();
    } else {
        cursor.moveToFirst();
        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DISPLAY_NAME);
        imageNameList.add(cursor.getString(idx));
        Log.i("FineName: ", cursor.getString(idx));
        cursor.close();
    }
}
my plan is to create a gallery of images showing respective names below it.

String filename = path.substring(path.lastIndexOf("/") + 1);