JSONObject.append into object - result is nested array?

Question

Following code produces a nested array as a result for keys containing three items:

import org.codehaus.jettison.json.JSONObject;
// ...

JSONObject ret = new JSONObject();
for (Key key:keys) ret.append("blocked",key.id());

The result is:

{"blocked": [[["1"],"2"],"3"]}

Is this expected? If it is, how can I construct a plain array adding item by item?

this depends on which library you use, could you specify the full package name for JSONObject — Alexey A., Jul 02 '12 at 16:09

legege · Accepted Answer · 2012-07-02T16:33:02.847

9

You need to create a JSONArray object:

JSONObject ret = new JSONObject();
JSONArray arr = new JSONArray();
arr.put("1");
arr.put("2");
arr.put("3");
ret.put("blocked", arr);

The result is:

{"blocked":["1","2","3"]}

edited Jul 02 '12 at 16:33

answered Jul 02 '12 at 16:20

legege

421
4
12

1

I would say this is more a work around. As Thomas says, the append function should do the same but more compact. – Daniel Alder Mar 31 '14 at 11:32

score 3 · Answer 2 · edited May 15 '13 at 07:58

It's curious because the API says the following:

Append values to the array under a key. If the key does not exist in the JSONObject, then the key is put in the JSONObject with its value being a JSONArray containing the value parameter. If the key was already associated with a JSONArray, then the value parameter is appended to it.

But it doesn't work correctly. When I do:

JSONObject o = new JSONObject();
o.append("arr", "123");
o.append("arr", "456");

I get an Exception saying that "JSONObject[arr] is not a JSONArray". It looks like there is a bug.

buttonius · Answer 3 · 2018-03-19T15:02:37.040

0

I ran into a similar problem. You should use the put method; not the append method. And, of course, you should create a JSONArrray and use that as the second argument of the put method.

edited Mar 19 '18 at 15:02

answered Mar 19 '18 at 14:57

buttonius

39
3

JSONObject.append into object - result is nested array?

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