Json String to Array

Question

I'm trying to fetch a JSON string to an object array in GWT.

My JSON string is here: https://api.guildwars2.com/v1/wvw/matches.json

{"wvw_matches":[{"wvw_match_id":"2-6","red_world_id":2102,"blue_world_id":2105,"green_world_id":2205,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"1-2","red_world_id":1005,"blue_world_id":1009,"green_world_id":1016,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"1-6","red_world_id":1022,"blue_world_id":1012,"green_world_id":1018,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"2-4","red_world_id":2101,"blue_world_id":2014,"green_world_id":2204,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"2-9","red_world_id":2011,"blue_world_id":2008,"green_world_id":2006,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"1-5","red_world_id":1007,"blue_world_id":1002,"green_world_id":1004,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"2-3","red_world_id":2103,"blue_world_id":2012,"green_world_id":2003,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"2-1","red_world_id":2202,"blue_world_id":2002,"green_world_id":2010,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"1-1","red_world_id":1019,"blue_world_id":1017,"green_world_id":1008,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"2-5","red_world_id":2104,"blue_world_id":2301,"green_world_id":2013,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"2-8","red_world_id":2004,"blue_world_id":2001,"green_world_id":2009,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"2-7","red_world_id":2005,"blue_world_id":2207,"green_world_id":2206,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"1-3","red_world_id":1021,"blue_world_id":1003,"green_world_id":1014,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"2-2","red_world_id":2007,"blue_world_id":2203,"green_world_id":2201,"start_time":"2014-08-22T18:00:00Z","end_time":"2014-08-29T18:00:00Z"},
{"wvw_match_id":"1-4","red_world_id":1015,"blue_world_id":1023,"green_world_id":1011,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"1-7","red_world_id":1006,"blue_world_id":1001,"green_world_id":1010,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"},
{"wvw_match_id":"1-8","red_world_id":1024,"blue_world_id":1020,"green_world_id":1013,"start_time":"2014-08-23T01:00:00Z","end_time":"2014-08-30T01:00:00Z"}]}

My code:

try {
      Request request = builder.sendRequest(null, new RequestCallback() {


        @Override
        public void onResponseReceived(Request request, Response response)
        {
             if (200 == response.getStatusCode()) {
                 Window.alert(response.getText());
                    updateTable(JsonUtils.<JsArray<JSONreceiverGW>>safeEval(response.getText()));
             }else{
                 Window.alert("Couldn't retrieve JSON " + response.getStatusText());

             }

        }

        @Override
        public void onError(Request request, Throwable exception)
        {
             Window.alert("Couldn't retrieve JSON");

        }
      });
    } catch (RequestException e) {
         Window.alert("Couldn't retrieve JSON");
    }

     private void updateTable(JsArray<JSONreceiverGW> jsArray) {

      for (int i = 0; i < jsArray.length(); i++) {
          Window.alert(jsArray.get(i).getmatchID());
        }


 }

I get the error:

Something other than an int was returned from JSNI method '@com.google.gwt.core.client.JsArray::length()': JS value of type undefined, expected int

Thomas Broyer · Accepted Answer · 2014-08-29 08:38:16Z

2

What you receive is not an array, it's an object with a property whose value is an array (and that object does not have a length property, hence the undefined). You need a JSO for the container object:

public class JSONreceiverGWContainer extends JavaScriptObject {
  protected JSONreceiverGWContainer() {}

  public final JsArray<JSONreceiverGW> getWvwMatches() /*-{ return this.wvw_matches; }-*/;
}

then you'll do something like the following (split on two line for readability):

JSONreceiverGWContainer container = JsonUtils.safeEval(response.getText());
updateTable(container.getWvwMatches());

answered Aug 29, 2014 at 8:38

Thomas Broyer

64.6k7 gold badges95 silver badges165 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Json String to Array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related