Null pointer Exception when using volley - nullpointerexception

Question

i am using volley to fetch data from database.I always get null pointer error. I don't know whats the error. it always executes onErrorResponse() (error.null) and shows this in my logcat
BasicNetwork.performRequest: Unexpected response code 301
here is my java method to fetch data from php file .
private void fetchChatThread() {
StringRequest strReq = new StringRequest(Request.Method.POST,
EndPoints.chatMessages, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
try {
JSONObject obj = new JSONObject(response);
Load_datato_list load_data_tolist = new Load_datato_list();
load_data_tolist.execute(obj);
} catch (JSONException e) {
Log.e(TAG, "json parsing error: " + e.getMessage());
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Messages messages=new Messages();
error.printStackTrace();
NetworkResponse networkResponse = error.networkResponse;
Log.e(TAG, " Try Again fetch error" + networkResponse);
Toast.makeText(Chat_Rooms.this, messages.getSender_id(), Toast.LENGTH_SHORT).show();
}
}) {
#Override
protected Map<String, String> getParams() {
Map<String, String> myparams = new HashMap<String, String>();
try {
myparams.put("sender_userid", sender_userid);
myparams.put("reciver_id", String_username.reciver_user_id);
} catch (Exception e) {
e.printStackTrace();
}
Log.e(TAG, "Params: " + myparams.toString());
return myparams;
}
};
//Adding request to request queue
addToRequestQueue(strReq);
}
here is my private that loads data from php to objects
private class Load_datato_list extends AsyncTask<JSONObject, Void, ArrayList<Messages>> {
#Override
protected ArrayList<Messages> doInBackground(JSONObject[] params) {
JSONObject obj = params[0];
try {
JSONArray commentsObj = obj.getJSONArray("messages");
for (int i = 0; i < commentsObj.length(); i++) {
JSONObject commentObj = (JSONObject) commentsObj.get(i);
String commentId = commentObj.getString("id");
String commentText = commentObj.getString("message");
String createddate = commentObj.getString("date");
String commentuser_id = commentObj.getString("user_id_fk");
URL url;
Bitmap image, image1;
try {
url = new URL(Base_URL.BASE_URL_IMAGES + "user_profile_pictures" + commentuser_id + ".jpg");
image1 = BitmapFactory.decodeStream(url.openStream());
image = getResizedBitmap(image1, 50);
} catch (Exception e) {
image = null;
e.printStackTrace();
}
Users user;
user = new Users(commentuser_id, String_username.user_name, image);
Messages message = new Messages();
message.setId(commentId);
message.setMessage(commentText);
message.setCreatedAt(createddate);
message.setSender_id(commentuser_id);
message.setUser(user);
messageArrayList.add(message);
}
} catch (Exception e) {
e.printStackTrace();
}
return messageArrayList;
}
#Override
protected void onPostExecute(ArrayList<Messages> messageArrayList) {
Collections.reverse(messageArrayList);
chatroom_adapter.notifyDataSetChanged();
if (chatroom_adapter.getItemCount() > 1) {
rec_chatBubble.getLayoutManager().smoothScrollToPosition(rec_chatBubble, null, chatroom_adapter.getItemCount() - 1);
}
}
}

Answer 1

TRY THIS
private void fetchChatThread(final String count) {
StringRequest strReq = new StringRequest(Request.Method.POST,
EndPoints.chatMessages, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
try {
JSONObject obj = new JSONObject(response);
Log.d("response error", response);
Load_datato_list load_data_tolist = new Load_datato_list();
load_data_tolist.execute(obj);
} catch (JSONException e) {
Log.e(TAG, "json parsing error: " + e.getMessage());
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Messages messages = new Messages();
error.printStackTrace();
NetworkResponse networkResponse = error.networkResponse;
Log.e(TAG, " Try Again fetch error" + networkResponse);
}
}) {
#Override
protected HashMap<String, String> getParams() {
HashMap<String, String> myparams = new HashMap<String, String>();
try {
myparams.put("sender_userid", sender_userid);
myparams.put("reciver_id", String_username.reciver_user_id);
myparams.put("count", count);
} catch (Exception e) {
e.printStackTrace();
}
Log.e(TAG, "Params: " + myparams.toString());
return myparams;
}
};
//Adding request to request queueok
addToRequestQueue(strReq);
}
AND THIS
private class Load_datato_list extends AsyncTask<JSONObject, Void, ArrayList<Messages>> {
#Override
protected ArrayList<Messages> doInBackground(JSONObject[] params) {
messageArrayList.clear();
JSONObject obj = params[0];
try {
JSONArray commentsObj = obj.getJSONArray("messages");
for (int i = 0; i < commentsObj.length(); i++) {
JSONObject commentObj = (JSONObject) commentsObj.get(i);
String Id = commentObj.getString("id");
String Text = commentObj.getString("message");
String date = commentObj.getString("date");
String yuser_id = commentObj.getString("user_id");
Messages message = new Messages();
message.setId(Id);
message.setMessage(Text);
message.setCreatedAt(date);
message.setSender_id(yuser_id);
messageArrayList.add(message);
}
} catch (Exception e) {
e.printStackTrace();
}
return messageArrayList;
}