Android JSONArray to ArrayList

Question

I am trying to parse a JSONArray into and ArrayList in my android app. The PHP script correctly retuns the expected results, however the Java fails with a null pointer excep

Answer 1

Use custom method which convert your JSONArray to List instead of iterate and build List.

How to call :

try {
     ArrayList> list = (ArrayList>) toList(json);
} catch (JSONException e) {
     e.printStackTrace();
}

Convert json array to List :

private List toList(JSONArray array) throws JSONException {
    List list = new ArrayList();
    int size = array.length();
    for (int i = 0; i < size; i++) {
        list.add(fromJson(array.get(i)));
    }
    return list;
}

Convert json to Object :

private Object fromJson(Object json) throws JSONException {
    if (json == JSONObject.NULL) {
        return null;
    } else if (json instanceof JSONObject) {
        return jsonToMap((JSONObject) json);
    } else if (json instanceof JSONArray) {
        return toList((JSONArray) json);
    } else {
        return json;
    }
}

Convert json to map :

public Map jsonToMap(JSONObject object) throws JSONException {
    Map map = new HashMap();
    Iterator keys = object.keys();
    while (keys.hasNext()) {
        String key = (String) keys.next();
        map.put(key, fromJson(object.get(key)).toString());
    }
    return map;
}