Android volley sending data twice

No need to use connection.setChunkedStreamingMode(0); to avoid volley sending data twice bug. you need to set retry policy for current request :

JsonObjectRequest jsonObjReq = new JsonObjectRequest(...);
jsonObjReq.setRetryPolicy(new DefaultRetryPolicy(
                       0,
                       DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                       DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));