NetworkDispatcher.run: Unhandled exception java.lang.NullPointerException

Question

I am trying to run below code to send request on my web server API using volley library this is my Make web server hit functions. check my code and tell ma where is the problem

    private void makeLoginRequest(String mEmail, String mPassword) {
        String urlJsonObj = Constants.WebUrls.baseUrl + Constants.BaseUrlPrefix.dgetLogin;
        showpDialog();
        Map<String, String> params = new HashMap<String, String>();
        params.put("email", mEmail);
        params.put("password", mPassword);
        params.put("signature", Utility.getmd5SignatureMAin(this));
        params.put("ts", Utility.getTimeStamp());
        params.put("client_id", Constants.clientID);
        params.put("platforms", Constants.plateForm);    AppController.getInstance().getSharedPrefrence().getPrefsKeyObjectId(this));
        params.put("parse_installation", AppController.getInstance().getSharedPrefrence().getdPrefsKeyInstallationId(this));


        CustomRequest jsObjRequest = new CustomRequest(Request.Method.POST, urlJsonObj, params, this.createRequestSuccessListener(), this.createRequestErrorListener());

    }


    public Response.Listener<JSONObject> createRequestSuccessListener() {
        Response.Listener<JSONObject> reponseListener;
        reponseListener = new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject jsonObject) {
                try {
                    if (jsonObject != null)
                        parseLogin(jsonObject);
                    else{
                        Log.e("ABC","DEF");
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                hidepDialog();


            }
        };
        return reponseListener;
    }

    Response.ErrorListener createRequestErrorListener() {
        Response.ErrorListener errorListener;
        errorListener = new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError volleyError) {
                volleyError.printStackTrace();
                hidepDialog();
                if (volleyError.networkResponse == null) {
                    if (volleyError.getClass().equals(TimeoutError.class)) {
                        // Show timeout error message
                        Toast.makeText(DLoginActivity.this,
                                "Oops. Timeout error!",
                                Toast.LENGTH_SHORT).show();

                    }
                    if ( volleyError.getClass().equals(NoConnectionError.class)) {
                    // Show timeout error message
                        Toast.makeText(DLoginActivity.this,
                        "No Internet Connection! Try Again Later",
                        Toast.LENGTH_SHORT).show();
                    }
                }
            }
        };
        return errorListener;
    }

But I am getting following error:

E/Volley: [4189] NetworkDispatcher.run: Unhandled exception java.lang.NullPointerException java.lang.NullPointerException at libcore.net.UriCodec.encode(UriCodec.java:132) at java.net.URLEncoder.encode(URLEncoder.java:57) at com.android.volley.Request.encodeParameters(Request.java:449) at com.android.volley.Request.getBody(Request.java:435) at com.android.volley.toolbox.HurlStack.addBodyIfExists(HurlStack.java:236) at com.android.volley.toolbox.HurlStack.setConnectionParametersForRequest(HurlStack.java:210) at com.android.volley.toolbox.HurlStack.performRequest(HurlStack.java:106) at com.android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:93) at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:110)

I have no idea what is to problem. Can anyone help? Thanks in advance.