How do you parse a JSON Array w/o a defined array?

Question

My question is almost identical to the one below.

Forgot to mention this thread as well: Parse json array android

I'm parsing the following data. https://api.tfl.gov.uk/Line/Mode/tube%2Cdlr

I just need to extract "id" and "name". Like in the thread above, the data is enclosed in square brackets but not in a specific array. I need to parse a JSON object and then return the data in an ArrayList. I know how to parse an ArrayList. When parsing, do I create a JSON object or a JSON Array? Is it possible to create and parse a JSONObject and then convert it to and return it in an array?

In the first example they use HashMap. Is it possible to parse it w/o HashMap and GSON? And in the second thread, they extract the data from the Url in the try catch method. I implemented BuildUrl method in a separate class.

P.S. I haven't tested the code yet.

JSONUtils class:

public class JSONUtils
{
    /**
     * Tag for the log messages
     */
    private static final String LOG_TAG = JSONUtils.class.getSimpleName();

    private static final String KEY_LINE_ID = "id";
    private static final String KEY_LINE_NAME = "name";


    public JSONUtils()
    {
    }

    public static Lines extractFeatureFromJson (String linesJSON)
    {
        // If the JSON string is empty or null, then return early.
        if (TextUtils.isEmpty(linesJSON)) {
            return null;
        }

        Lines line = null;
        try
        {
            // Create a JSONObject from the JSON file
            JSONObject jsonObject = new JSONObject(linesJSON);

            String id = "";
            if (jsonObject.has("id"))
            {
                id = jsonObject.optString(KEY_LINE_ID);
            }


            String name = "";
            if (jsonObject.has("name"))
            {
                name= jsonObject.optString(KEY_LINE_NAME);
            }

            line = new Lines(id, name);
    }
        catch (JSONException e)
    {
        // If an error is thrown when executing any of the above statements in the "try" block,
        // catch the exception here, so the app doesn't crash. Print a log message
        // with the message from the exception.
        Log.e("QueryUtils", "Problem parsing lines JSON results", e);

    }
        // Return the list of lines
        return line;
}
}

@DemiDust@RobertHarvey. I'd like to return an ArrayList. My url method is in a separate class. — LeadBox4
– LeadBox4, Commented Jan 4, 2019 at 4:24
@RobertHarvey I know how to parse an Array. In this structure, I need to parse a JSON object and then return the data in an ArrayList. The question you marked as identical to me has a different JSON structure. — LeadBox4
– LeadBox4, Commented Jan 4, 2019 at 4:39
You should probably be saying this in your question, instead of all that. — Robert Harvey
– Robert Harvey, Commented Jan 4, 2019 at 4:41

ॐ Rakesh Kumar · Accepted Answer · 2019-01-04 05:34:27Z

You can try like this following:

You will have to pass your response and I just put all your response in String. You can pass your own response from API on that behalf.

 String response="[{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"bakerloo\",\"name\":\"Bakerloo\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.303Z\",\"modified\":\"2018-12-11T17:06:05.303Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Bakerloo&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"central\",\"name\":\"Central\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.3Z\",\"modified\":\"2018-12-11T17:06:05.3Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Central&serviceTypes=Regular\"},{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Night\",\"uri\":\"/Line/Route?ids=Central&serviceTypes=Night\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"circle\",\"name\":\"Circle\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.3Z\",\"modified\":\"2018-12-11T17:06:05.3Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Circle&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"district\",\"name\":\"District\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.3Z\",\"modified\":\"2018-12-11T17:06:05.3Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=District&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"dlr\",\"name\":\"DLR\",\"modeName\":\"dlr\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.303Z\",\"modified\":\"2018-12-11T17:06:05.303Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=DLR&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"hammersmith-city\",\"name\":\"Hammersmith & City\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.297Z\",\"modified\":\"2018-12-11T17:06:05.297Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Hammersmith & City&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"jubilee\",\"name\":\"Jubilee\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.297Z\",\"modified\":\"2018-12-11T17:06:05.297Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Jubilee&serviceTypes=Regular\"},{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Night\",\"uri\":\"/Line/Route?ids=Jubilee&serviceTypes=Night\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"metropolitan\",\"name\":\"Metropolitan\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.297Z\",\"modified\":\"2018-12-11T17:06:05.297Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Metropolitan&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"northern\",\"name\":\"Northern\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.3Z\",\"modified\":\"2018-12-11T17:06:05.3Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Northern&serviceTypes=Regular\"},{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Night\",\"uri\":\"/Line/Route?ids=Northern&serviceTypes=Night\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"piccadilly\",\"name\":\"Piccadilly\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.3Z\",\"modified\":\"2018-12-11T17:06:05.3Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Piccadilly&serviceTypes=Regular\"},{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Night\",\"uri\":\"/Line/Route?ids=Piccadilly&serviceTypes=Night\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"victoria\",\"name\":\"Victoria\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.297Z\",\"modified\":\"2018-12-11T17:06:05.297Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Victoria&serviceTypes=Regular\"},{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Night\",\"uri\":\"/Line/Route?ids=Victoria&serviceTypes=Night\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}},{\"$type\":\"Tfl.Api.Presentation.Entities.Line, Tfl.Api.Presentation.Entities\",\"id\":\"waterloo-city\",\"name\":\"Waterloo & City\",\"modeName\":\"tube\",\"disruptions\":[],\"created\":\"2018-12-11T17:06:05.297Z\",\"modified\":\"2018-12-11T17:06:05.297Z\",\"lineStatuses\":[],\"routeSections\":[],\"serviceTypes\":[{\"$type\":\"Tfl.Api.Presentation.Entities.LineServiceTypeInfo, Tfl.Api.Presentation.Entities\",\"name\":\"Regular\",\"uri\":\"/Line/Route?ids=Waterloo & City&serviceTypes=Regular\"}],\"crowding\":{\"$type\":\"Tfl.Api.Presentation.Entities.Crowding, Tfl.Api.Presentation.Entities\"}}]\n";

        try {
            JSONArray jsArray=new JSONArray(response);
            for(int i=0;i<jsArray.length();i++)
            {
                String id=jsArray.getJSONObject(i).getString("id");
                String name=jsArray.getJSONObject(i).getString("name");

            }

        } catch (JSONException ex) {
            ex.printStackTrace();

        }

It will give you id and name

Comments are not for extended discussion; this conversation has been moved to chat.

Collectives™ on Stack Overflow

How do you parse a JSON Array w/o a defined array?

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related