How to Parse a Local JSON File from Assets Folder into a Listview

How can I parse a local JSON file from assets folder into a ListView?

As Faizan describes in their answer here:

First of all read the Json File from your assests file using below code.

and then you can simply read this string return by this function as

public String loadJSONFromAsset() {
    String json = null;
    try {
        InputStream is = getActivity().getAssets().open("yourfilename.json");
        int size = is.available();
        byte[] buffer = new byte[size];
        is.read(buffer);
        is.close();
        json = new String(buffer, "UTF-8");
    } catch (IOException ex) {
        ex.printStackTrace();
        return null;
    }
    return json;
}

and use this method like that

    try {
        JSONObject obj = new JSONObject(loadJSONFromAsset());
        JSONArray m_jArry = obj.getJSONArray("formules");
        ArrayList<HashMap<String, String>> formList = new ArrayList<HashMap<String, String>>();
        HashMap<String, String> m_li;

        for (int i = 0; i < m_jArry.length(); i++) {
            JSONObject jo_inside = m_jArry.getJSONObject(i);
            Log.d("Details-->", jo_inside.getString("formule"));
            String formula_value = jo_inside.getString("formule");
            String url_value = jo_inside.getString("url");

            //Add your values in your `ArrayList` as below:
            m_li = new HashMap<String, String>();
            m_li.put("formule", formula_value);
            m_li.put("url", url_value);

            formList.add(m_li);
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }

For further details regarding JSON Read HERE

How to parse json from a local json file into a ListView in android?

create a customList class(dont use hashmap)

change your custom list code (this is your code)

public class CustomList extends ArrayAdapter<String>
{
public final ArrayList<HashMap<String, String>> urlist;
private Activity context;

public CustomList(Activity context,ArrayList<HashMap<String, String>> urlist) 
{
    super(context, R.layout.list_single);
    this.context = context;
    this.urlist=urlist;

}
@Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView= inflater.inflate(R.layout.list_single, null, true);

TextView txtTitle = (TextView) rowView.findViewById(R.id.txt);
txtTitle.setText((CharSequence) urlist);
return rowView;

 }
 }

to

public class customList extends ArrayAdapter<String>{

Context context; 
int layoutResourceId;    
ArrayList<String> data = null;

public customList(Context context, int layoutResourceId, ArrayList<String> data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    CustomHolder holder = null;

    if(row == null)
    {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new CustomHolder();
        holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);

        row.setTag(holder);
    }
    else
    {
        holder = (CustomHolder)row.getTag();
    }

    String s = data.get(postition);
    holder.txtTitle.setText(s);

    return row;
}

static class CustomHolder
{
    TextView txtTitle;
}
}

and change your json parsing code and parse your json like

 // JSONArray has four JSONObject

     ArrayList<String> messages = new ArrayList<String>();
        for (int i = 0; i < jsonArray.length(); i++) {

            // Creating JSONObject from JSONArray
            JSONObject jsonObj = jsonArray.getJSONObject(i);

            // Getting data from individual JSONObject
            String message = jsonObj.getString("msg");
            messages.add(message);

        }

and finally replace your this code

CustomList adapter = new CustomList(MainActivity.this,urlist);
    list=(ListView)findViewById(R.id.list);
    list.setAdapter(adapter);
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() 
    {

         @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    Toast.makeText(MainActivity.this, "TEST.........", Toast.LENGTH_SHORT).show();

                }
            });

with this one

customList adapter = new customList(MainActivity.this,R.layout.list_single,messages);  //messagses is your arraylist in which you added string by parsing your json (see before this code mean upward)
    list=(ListView)findViewById(R.id.list);
    list.setAdapter(adapter);
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() 
    {

         @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    Toast.makeText(MainActivity.this, "TEST.........", Toast.LENGTH_SHORT).show();

                }
            });

Solution 2

since you are showing only single text , you dont need to create your own custom adapter instead you can simply do.

 ArrayList<String> messages = new ArrayList<String>();
        for (int i = 0; i < jsonArray.length(); i++) {

            // Creating JSONObject from JSONArray
            JSONObject jsonObj = jsonArray.getJSONObject(i);

            // Getting data from individual JSONObject
            String message = jsonObj.getString("msg");
            messages.add(message);

        }

  ArrayAdapter<String> adapter = new ArrayAdapter<String>(MainActivity.this,
                android.R.layout.simple_list_item_1, messages);
  list=(ListView)findViewById(R.id.list);
    list.setAdapter(adapter);
    list.setOnItemClickListener(new AdapterView.OnItemClickListener() 
    {

         @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    Toast.makeText(MainActivity.this, "TEST.........", Toast.LENGTH_SHORT).show();

                }
            });

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