Simple parse JSON from URL on Android and display in listview or spinner

Question

I'm trying to parse a JSON result fetched from a URL in my app

I have tried a few examples on the Internet, but I couldn't make them working.

The data looks like this:

[{"objectno":"CarlosG","objectname":"MJ1196H00167","objecttype":"car_station_wagon","postext":"11 km norte de Monterrey, en San Nicolás De Los Garza NL, Carretera Monterrey-Nuevo Laredo MEX-85 ","ignition":1,"drivername":"Carlos Gutierrez","longitude_mdeg":-100292728,"latitude_mdeg":25765772},{"objectno":"Demo","objectname":"MJ1196H00169","objecttype":"car","postext":"Adsum Culiacán Rosales, Calle Río San Lorenzo ","ignition":1,"drivername":"AutoDemo","longitude_mdeg":-107392146,"latitude_mdeg":24794140},{"objectno":"GustavoC","objectname":"MJ6146H01742","objecttype":"car_station_wagon","postext":"En Guadalajara JA, Calle George Frideric Handel / Calle A Las Montañas ","ignition":0,"drivername":"Gustavo Cortez","longitude_mdeg":-103421146,"latitude_mdeg":20675859}]

JSON FORMATTED

[

    {
        "objectno":"CarlosG",
        "objectname":"MJ1196H00167",
        "objecttype":"car_station_wagon",
        "postext":"11 km norte de Monterrey, en San Nicolás De Los Garza NL, Carretera Monterrey-Nuevo Laredo MEX-85 ",
        "ignition":1,
        "drivername":"Carlos Gutierrez",
        "longitude_mdeg":-100292728,
        "latitude_mdeg":25765772
    },
    {
        "objectno":"Demo",
        "objectname":"MJ1196H00169",
        "objecttype":"car",
        "postext":"Adsum Culiacán Rosales, Calle Río San Lorenzo ",
        "ignition":1,
        "drivername":"AutoDemo",
        "longitude_mdeg":-107392146,
        "latitude_mdeg":24794140
    },
    {
        "objectno":"GustavoC",
        "objectname":"MJ6146H01742",
        "objecttype":"car_station_wagon",
        "postext":"En Guadalajara JA, Calle George Frideric Handel / Calle A Las Montañas ",
        "ignition":0,
        "drivername":"Gustavo Cortez",
        "longitude_mdeg":-103421146,
        "latitude_mdeg":20675859
    }

]

I need it in a listview or a spinner.

What's the simplest way to fetch the URL and parse the JSON data show it in the listview or spinner ?

Thanks

Answer 1

You have to create a modal class and List View Adapter.

  Model.java

  public class Model {
     String field1, field2,... fieldn;

     public Model(JSONObject object) {
         field1 = object.optString("key1");
         field1 = object.optString("key2");
         .
         .
         fieldn = object.optString("keyn");
     }

     //getter methods of each fields (You've an option to auto generate them in Android Studio
}

Now from the Activity class create an ArrayList like this

 ArrayList<Model> models = new ArrayList<>;
 for (int i = 0; i < jsonArray.length(); i++) {
     models.add(new Model(jsonArray.getJSONObject()));
 }

 //Populate List View
 ListView lv = findViewById(R.id.lv);
 CustomAdapter adapter = new CustomAdapter(models);
 lv.setAdapter(adapter);


 //Create a new class for the Custom adapter extending the BaseAdapter

 class CustomAdapter extends BaseAdapter {
         ArrayList<Model> models;

         public CustomAdapter(ArrayList<Model> models) {
             this.models = models;
         }

         View getView(...) {
             //Create your item view here
             // Use a ViewHolder to hold the Views

             //Access the data from the model
             Model model = (Model) getItem(position);

             holder.textView.setText(model.getField1());
              ........
              ........

             return convertView;
         }

         Object getItem(int position) {
              return models.get(position);
         }
}

I've given a model. Modify the classes to incorporate your changes.