datafile4 datafile4 - 3 months ago 64
JSON Question

Volley JSONArrayRequest with JSONObject as parameter

I need to make a request with a JSONObject as follows:

{
'LangIDs': [1, 2],
'GenreIDs': [4],
'LowPrice': 0,
'HighPrice': 999,
'SearchTerms': [],
'Pagination': {
'PageNumber': 0,
'PageLength': 10
}
}


The expected response is a JSONArray. Using Volley, I can't make a JsonArrayRequest with a JSONObject parameter.

Before I made the request this way:

StringRequest jsonObjectRequest = new StringRequest(Request.Method.POST, url, new Response.Listener < String > () {
@Override
public void onResponse(String response) {
JSONObject jsonObject;
int id;
String bookName;
String Url;
try {
responseArray = new JSONArray(response);
} catch (JSONException e) {

}

for (int i = 0; i < response.length(); i++) {
try {
jsonObject = responseArray.getJSONObject(i);
id = jsonObject.getInt(Constants.KEY_ID);
bookName = jsonObject.getString(Constants.KEY_BOOKNAME);
Url = imgUrl + jsonObject.getString(Constants.KEY_IMG_URL);
books.add(new Book(id, bookName, Url));

} catch (JSONException e) {
e.printStackTrace();
}
}
mAdapter.updateGrid(books);
Log.v("Response", response);
}
}, new Response.ErrorListener() {@
Override
public void onErrorResponse(VolleyError error) {
Log.e("Error:", error.getMessage());
}
}) {@
Override
protected Map < String, String > getParams() throws AuthFailureError {
HashMap < String, String > params = new HashMap < > ();
String message = getArguments().getString(Constants.KEY_FILTER_VALUES);
Log.v("FilterMessage", message);
params.put(Constants.KEY_PAGENUMBER, String.valueOf(0));
params.put(Constants.KEY_PAGELENGTH, String.valueOf(10));
return params;
}
};


But now it is JSONObject that contains JSONObject.

How now I can make this request using Volley?

Answer

I created a custom volley request that accepts a JSONObject as parameter.

CustomJsonArrayRequest.java

 public class CustomJsonArrayRequest extends JsonRequest<JSONArray> {

        /**
         * Creates a new request.
         * @param method the HTTP method to use
         * @param url URL to fetch the JSON from
         * @param jsonRequest A {@link JSONObject} to post with the request. Null is allowed and
         *   indicates no parameters will be posted along with request.
         * @param listener Listener to receive the JSON response
         * @param errorListener Error listener, or null to ignore errors.
         */
        public CustomJsonArrayRequest(int method, String url, JSONObject jsonRequest,
                                Listener<JSONArray> listener, ErrorListener errorListener) {
            super(method, url, (jsonRequest == null) ? null : jsonRequest.toString(), listener,
                    errorListener);
        }

        @Override
        protected Response<JSONArray> parseNetworkResponse(NetworkResponse response) {
            try {
                String jsonString = new String(response.data,
                        HttpHeaderParser.parseCharset(response.headers, PROTOCOL_CHARSET));
                return Response.success(new JSONArray(jsonString),
                        HttpHeaderParser.parseCacheHeaders(response));
            } catch (UnsupportedEncodingException e) {
                return Response.error(new ParseError(e));
            } catch (JSONException je) {
                return Response.error(new ParseError(je));
            }
        }
    }

How to use?

JSONObject body = new JSONObject();
// Your code
CustomJsonArrayRequest req = new CustomJsonArrayRequest(Request.Method.POST, url, body, success, error);