Question

I need help with parsing json string in Java Android Appl.

Text of JSON file:

{"data":{"columns":["location_id","name","description","latitude","longitude","error","type","type_id","icon_media_id","item_qty","hidden","force_view"],"rows":[[2,"Editor","",43.076014654537,-89.399642451567,25,"Npc",1,0,1,"0","0"],[3,"Dow Recruiter","",43.07550842555,-89.399381822662,25,"Npc",2,0,1,"0","0"] [4,"Protestor","",43.074933,-89.400438,25,"Npc",3,0,1,"0","0"],[5,"State Legislator","",43.074868061524,-89.402136196317,25,"Npc",4,0,1,"0","0"],[6,"Marchers Bascom","",43.075296413877,-89.403374183615,25,"Node",22,0,1,"0","0"] [7,"Mary","",43.074997865584,-89.404967573966,25,"Npc",7,0,1,"0","0"]]},"returnCode":0,"returnCodeDescription":null}

How can get values: location_id, name, latitude, longitude.
Thanks, Michal.

Answer 1

Using manual parsing you can implement it like this:

            JSONArray  pages     =  new JSONArray(jsonString);
            for (int i = 0; i < pages.length(); ++i) {
                JSONObject rec = pages.getJSONObject(i);
                JSONObject jsonPage =rec.getJSONObject("page");
                String address = jsonPage.getString("url");
                String name = jsonPage.getString("name");
                String status =  jsonPage.getString("status");
}

in your case note that your outer elemnt data is type of JSONObject and then you have a JSONArray

mine json file:

[{"page":{"created_at":"2011-07-04T12:01:00Z","id":1,"name":"Unknown Page","ping_at":"2011-07-04T12:06:00Z","status":"up","updated_at":"2011-07-04T12:01:00Z","url":"http://www.iana.org/domains/example/","user_id":2}},{"page":{"created_at":"2011-07-04T12:01:03Z","id":3,"name":"Down Page","ping_at":"2011-07-04T12:06:03Z","status":"up","updated_at":"2011-07-04T12:01:03Z","url":"http://www.iana.org/domains/example/","user_id":2}}] 

note that mine starts from [, which means an array, but yours from { and then you have [ array inside. If you run it with a debugger, you can see exactly what´s inside your json objects.

There are also better approaches like:

1. Jackson
2. Jackson-JR (light-weight Jackson)
3. GSON

All of them can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object.