Adding Request Headers و Adding Post Parameters

دوستان کسی راجع به این دو تیکه کد چیزی میدونه ؟ میتونه کمی توضیح بده ؟

Adding Request Headers

String tag_json_obj = "json_obj_req";

String
url
        = "https:// api.androidhive.info/volley/person_object.json";

ProgressDialog pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
pDialog.show();

JsonObjectRequest
jsonObjReq
        = new JsonObjectRequest(
        Method.POST,
        url,
        null,
        new Response.Listener() {

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

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

    @Override
    public Map getHeaders() throws AuthFailureError
    {
        HashMap headers = new HashMap();
        headers.put("Content-Type", "application/json");
        headers.put("apiKey", "xxxxxxxxxxxxxxx");
        return headers;
    }

};

AppController.getInstance()
        .addToRequestQueue(jsonObjReq, tag_json_obj); 

Adding Post Parameters

String tag_json_obj = "json_obj_req";

String
url
        = "https:// api.xyz.info/volley/person_object.json";

ProgressDialog pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...PLease wait");
pDialog.show();

JsonObjectRequest
jsonObjReq
        = new JsonObjectRequest(
        Method.POST,
        url,
        null,
        new Response.Listener() {

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

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

    @Override
    protected Map getParams()
    {
        Map params = new HashMap();
        params.put("name", "Androidhive");
        params.put("email", "[email protected]");
        params.put("password", "password123");

        return params;
    }

};

AppController.getInstance()
        .addToRequestQueue(jsonObjReq, tag_json_obj);