java primitive array to JSONArray

Question

I'm trying convert java primitive array to JSONArray, but I have strange behaviour.My code below.

long [] array = new long[]{1, 2, 3};
JSONArray jsonArray = new JSONArray(Arrays.asList(array));
jsonArray.toString();

output is ["[J@532372dc"]

Why Do I get this output? I want to get output like this [1, 2, 3]

`new JSONArray(array)` is sufficient to supply a (primitive) array to the constructor. — user2864740, Aug 12 '14 at 07:48

Rod_Algonquin · Accepted Answer · 2014-08-12T07:40:17.127

4

problem:

Arrays.asList(array)

You cant transform an array of primitive types to Collections that it needs to be an array of Objects type. Since asList expects a T... note that it needs to be an object.

why is it working?

That is because upon passing it in the parameter it will autoBox it since array are type object.

solution:

You need to change it to its wrapper class, and use it as an array.

sample:

Long[] array = new Long[]{1L, 2L, 3L};
JSONArray jsonArray = new JSONArray(Arrays.asList(array));
jsonArray.toString();

result:

[1, 2, 3]

edited Aug 12 '14 at 07:40

answered Aug 12 '14 at 07:34

Rod_Algonquin

26,074
6
52
63

You will need to cast the values of `array` to `long` or else it will give `Type mismatch: cannot convert from int to Long` – Apoorv Aug 12 '14 at 07:37
@Apoorv no need I can just directly add a modifier on it. – Rod_Algonquin Aug 12 '14 at 07:39
Yes you can do it either way. – Apoorv Aug 12 '14 at 07:39
About autoboxing http://stackoverflow.com/questions/1073919/how-to-convert-int-into-listinteger-in-java – vmtrue Aug 12 '14 at 08:09
How we can do reverse.? like i have have String[] and i want to convert it to json format like {'0','1','2'}. – Suresh Parmar May 13 '16 at 11:46

score 0 · Answer 2 · answered Jan 20 '22 at 13:29

0

If what you want is just to convert a primitive integer array to a JSONArray, cut the long story short.

JSONArray jsonArray = new JSONArray(Arrays.asList(longArray).get(0));

* You will need a try/catch block

answered Jan 20 '22 at 13:29

ucMedia

4,105
4
38
46

java primitive array to JSONArray

2 Answers2

Linked