How to bypass `null` values in JSON?

Question

How can I bypass an empty JSON value and give it a default value. This is my code:

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

    try {

        JSONArray foodArray = new JSONArray(foodJSON);

        for (int i = 0; i < foodArray.length(); i++) {

            JSONObject foodObject = foodArray.getJSONObject(i);

            ContentValues values = new ContentValues();
            values.put(COLUMN_NDB_NO, foodObject.getInt(COLUMN_NDB_NO));
            values.put(COLUMN_NAME, foodObject.getString(COLUMN_NAME));
            values.put(COLUMN_WATER_G, foodObject.getInt(COLUMN_WATER_G));
            values.put(COLUMN_ENERGY_KCAL, foodObject.getInt(COLUMN_ENERGY_KCAL));
            values.put(COLUMN_PROTEIN_G, foodObject.getInt(COLUMN_PROTEIN_G));
            values.put(COLUMN_LIPID_TOT_G, foodObject.getInt(COLUMN_LIPID_TOT_G));
            values.put(COLUMN_ASH_G, foodObject.getInt(COLUMN_ASH_G));
            values.put(COLUMN_CARBOHYDRT_G, foodObject.getInt(COLUMN_CARBOHYDRT_G));

            foodNutriProvider insert = new foodNutriProvider();

            insert.insert(CONTENT_URI,values);

        }

    } catch (JSONException e) {

        Log.e("foodSearch", "Problem parsing the earthquake JSON results", e);
        Log.e("foodSearch", foodJSON);
    }

    foodNutriProvider getTable = new foodNutriProvider();

    Cursor foodTable = getTable.query(CONTENT_URI, null, null, null, null);

    return foodTable;
}

The app crashes whenever it faces an empty field and for my app it doesn't really matter if its empty and I can give it a 0 instead.

You can create a POJO with default value and use that, instead of your JSON directly. https://stackoverflow.com/a/13466012/2520628 — Tejashwi Kalp Taru, Feb 11 '19 at 11:35

score 0 · Answer 1 · answered Feb 11 '19 at 11:36

0

I'm assuming that your app crashes with NUll Pointer error. If so, you must do a check for null values by using if condition.

answered Feb 11 '19 at 11:36

abhi

1,412
19
25

what error do you get? and from which line? please try to be a bit specific. – abhi Feb 12 '19 at 13:22

score 0 · Answer 2 · answered Feb 11 '19 at 12:08

0

For JSONObject :- foodJSONObject.isNull()

For JSONArray :- foodJSONArray.isNull(index)

For Getting values from a key :- foodJSONObject.optString("KEY_PARAMETER")

answered Feb 11 '19 at 12:08

Rohit Singh

403
4
9

if(foodObject.optString(COLUMN_WATER_G)==null){ values.put(COLUMN_WATER_G, 0); }else{ values.put(COLUMN_WATER_G, foodObject.getInt(COLUMN_WATER_G)); } this didnt work – K.hamdan Feb 11 '19 at 12:21
you need to use if(foodObject.optString(COLUMN_WATER).isNullorBlank()){ //****your code } – Rohit Singh Feb 12 '19 at 13:18

score 0 · Accepted Answer · answered Feb 11 '19 at 12:33

Instead of using getInt or getString with JSONObject , I will suggest you to use optInt or optString and it will automatically handle the null pointer exception for you and they are JSONObject internal method.

I have just replaced all getInt and getString with optInt and optString in your code, so request you to please check and let me know if this works for you.

Also, request you to please cross check the json data type you are trying to fetch from response. Like you are trying to fetch string and you are using getInt.

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

        try {

            JSONArray foodArray = new JSONArray(foodJSON);

            for (int i = 0; i < foodArray.length(); i++) {

                JSONObject foodObject = foodArray.getJSONObject(i);

                ContentValues values = new ContentValues();
                values.put(COLUMN_NDB_NO, foodObject.optInt(COLUMN_NDB_NO));
                values.put(COLUMN_NAME, foodObject.optString(COLUMN_NAME));
                values.put(COLUMN_WATER_G, foodObject.optInt(COLUMN_WATER_G));
                values.put(COLUMN_ENERGY_KCAL, foodObject.optInt(COLUMN_ENERGY_KCAL));
                values.put(COLUMN_PROTEIN_G, foodObject.optInt(COLUMN_PROTEIN_G));
                values.put(COLUMN_LIPID_TOT_G, foodObject.optInt(COLUMN_LIPID_TOT_G));
                values.put(COLUMN_ASH_G, foodObject.optInt(COLUMN_ASH_G));
                values.put(COLUMN_CARBOHYDRT_G, foodObject.optInt(COLUMN_CARBOHYDRT_G));

                foodNutriProvider insert = new foodNutriProvider();

                insert.insert(CONTENT_URI,values);

            }

        } catch (JSONException e) {

            Log.e("foodSearch", "Problem parsing the earthquake JSON results", e);
            Log.e("foodSearch", foodJSON);
        }

        foodNutriProvider getTable = new foodNutriProvider();

        Cursor foodTable = getTable.query(CONTENT_URI, null, null, null, null);

        return foodTable;
    }

How to bypass `null` values in JSON?

3 Answers3