عدم آپلود عکس با کتابخونه volley

من برای آپلود عکس از این کدها استفاده می کنم ولی متاسفانه آپلود نمیشه؟ خطایی هم نمیده

لطفا راهنمایی کنید ایا مشکلی توی کد هست؟

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);

  if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) {
    Uri filePath = data.getData();
    String[] filePathColumn = { MediaStore.Images.Media.DATA };
    Cursor cursor = getContentResolver().query(filePath, filePathColumn, null, null, null);
    cursor.moveToFirst();
    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
    String picturePath = cursor.getString(columnIndex);
    cursor.close();

    Bitmap myImg = BitmapFactory.decodeFile(picturePath);
    img_user.setImageBitmap(myImg);
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    myImg.compress(Bitmap.CompressFormat.PNG, 50, stream);
    byte[] bytes = stream.toByteArray();
    encodedString = Base64.encodeToString(bytes, 0);

  }
}

@Override
public void onClick(View view) {
  if (view == img_user) {
    showFileChooser();
  }
  if (view == button_authentication) {
    uploadImage();
  }
}




private void uploadImage() {

  StringRequest stringRequest = new StringRequest(Request.Method.POST, UPLOAD_URL,
    new Response.Listener<String>() {
      @Override
      public void onResponse(String s) {
        Toast.makeText(UserAccountActivity.this, s, Toast.LENGTH_LONG).show();
        try {
          JSONObject jsonObject = new JSONObject(s);
        } catch (JSONException e) {
          e.printStackTrace();
        }
      }
    },
    new Response.ErrorListener() {
      @Override
      public void onErrorResponse(VolleyError volleyError) {
        Toast.makeText(UserAccountActivity.this, volleyError.getMessage(), Toast.LENGTH_LONG).show();
      }
    }) {
    @Override
    protected Map<String, String> getParams() throws AuthFailureError {
      String image = encodedString;
      String name = edt_username.getText().toString().trim();
      SharedPreferences.Editor editor = G.sharedPreferences.edit();
      editor.putString("name",name);
      editor.apply();
      Map<String, String> params = new HashMap<String, String>();
      params.put("avatar", image);
      params.put("name", name);
      params.put("mobile_id", DatabaseOpenHelper.mobile_id);
      params.put("key", DatabaseOpenHelper.key);
      return params;
    }
  };
  RequestQueue requestQueue = Volley.newRequestQueue(this);
  requestQueue.add(stringRequest);
}