How to pull values from a json object that looks like "key":[10,12,56] with Java

Question

In wordpress an Api I use returns the tags' ids in an odd way, it returns in this ways:

"tags":[50,51,54]

I have never seen any Json that doesn't look like "key":"value", and I got no clue how to parse it... I hope you can help, Thank you!

Update: My bad, the example I posted was not a full json, it looks like that:

{"categories":[2,8],"tags":[50,51,54]}

that's because it is not a valid JSON.Is that full JSON you get? — Vladyslav Matviienko, Oct 20 '18 at 14:03
This is not valid JSON, but it would be if it looked like this: `{"tags":[50,51,54]}`. It is an object with a property `tags` which is an array of three numbers. — Henry, Oct 20 '18 at 14:03
you will be unable to create JSONObject from it. It will throw exception, as JsonObject can be created only from valid JSON — Vladyslav Matviienko, Oct 20 '18 at 14:09
@VladyslavMatviienko Why? This is a perfectly valid object (with the braces of course). — Henry, Oct 20 '18 at 14:10
The website jsoneditoronline.org does succeed to parse it... it seems as it's valid as Henry said, I just can't understand how to access it values... — Asaf, Oct 20 '18 at 14:13
Depending on the JSON library you use there might be a method `obj.getJSONArray("tags")` to access the array value. — Henry, Oct 20 '18 at 14:15
@NegevAsaf Hi Negev, why dont you try with below approach which i have mentioned in Answer. — GauravRai1512, Oct 20 '18 at 14:15
Possible duplicate of [How do I parse JSON in Android?](https://stackoverflow.com/questions/9605913/how-do-i-parse-json-in-android) — Vladyslav Matviienko, Oct 20 '18 at 14:16
I know how to Parse a Json... this is an irregular json, at least for me — Asaf, Oct 20 '18 at 14:20
this is 100% regular JSON. If it looks irregular to you, then `I know how to Parse a Json` is wrong — Vladyslav Matviienko, Oct 20 '18 at 14:21
But how can you access the values of a json that doesn't look like "key":"valuse"? Thanks! — Asaf, Oct 20 '18 at 14:23
Why don't you tell us which JSON library you are using? We could give a more useful answer. — Henry, Oct 20 '18 at 14:27

score 0 · Answer 1 · answered Oct 20 '18 at 14:24

You can create a class for this json string and parse the json with just one line of code as shown in main method.

public class Example {

    private List<Integer> categories = null;
    private List<Integer> tags = null;

    public List<Integer> getCategories() {
        return categories;
    }

    public void setCategories(List<Integer> categories) {
        this.categories = categories;
    }

    public List<Integer> getTags() {
        return tags;
    }

    public void setTags(List<Integer> tags) {
        this.tags = tags;
    }

    public static void main(String[] args) {
        String str = "{\"categories\":[2,8],\"tags\":[50,51,54]}";
        Example example = new Gson().fromJson(str, Example.class);
        System.out.println(example.getCategories());
        System.out.println(example.getTags());
    }
}

You need to have gson library for this and have this import,

import com.google.gson.Gson;

Hope this works for you.

score 0 · Accepted Answer · answered Oct 20 '18 at 14:33

The [] indicate that the tags are stored as an array. You can use JSONObject.getJSONArray() to access the array as a JSONArray object, then use .getInt() to retrieve the values. For example:

    String jsonString = "{\"categories\":[2,8],\"tags\":[50,51,54]}";
    JSONObject jsonObject = new JSONObject(jsonString);
    JSONArray tagsArray = jsonObject.getJSONArray("tags");
    // Transfer JSONArray to an int[] array.
    int tags[] = new int[tagsArray.length()];
    for (int i=0; i<tagsArray.length(); i++) {
        tags[i] = tagsArray.getInt(i);
    }

How to pull values from a json object that looks like "key":[10,12,56] with Java

2 Answers2