E/Volley：[2342] NetworkUtility.shouldRetryException：意外的响应代码 400

Question

I'm using the Android volley library and I'm trying to sending data to the API server but it responds to this error every time

E/Volley: [2342] NetworkUtility.shouldRetryException: Unexpected response code 400 for API

This is my code:

       JSONObject params = new JSONObject();
        try {
            params.put("deptcode", 649);
            params.put("endDt", "2021-07-22T12:37:28.755Z");
            params.put("instCode", 152);
            params.put("instSesNO", 0);
            params.put("locCode", 2);
            params.put("observedBy", obserName);
            params.put("sessionId", 0);
            params.put("startDt", "2021-07-22T12:37:28.755Z");
            params.put("status", "string");
        }
        catch (JSONException e) {
            e.printStackTrace();
        }

        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.POST,
                url, params,
                new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d("TAG", response.toString());
                    }
                }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d("TAG", "Error: " + error.getMessage());
            }
        }) {

            /**
             * Passing some request headers
             * */
            @Override
            public Map<String, String> getHeaders() throws AuthFailureError {
                HashMap<String, String> headers = new HashMap<String, String>();
                headers.put("Content-Type", "application/json; charset=utf-8");
                return headers;
            }

        };
        jsonObjReq.setRetryPolicy(new DefaultRetryPolicy(300000,
                DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

        MyRequestQueue.add(jsonObjReq);

I tried many ways but still doesn't work for me. Please help me.

Answer 1

normally 400 is a server error that is something not found on server.
1- try your api on postman and verify it is working.

2- sometimes, the value we're passing in int can be resolved by converting them to string.

3- try to get the error message from error.getMessage() . if not resolved, please share your api i'll check.