Convert a string which contains an array of json objects to an array in Java

Question

I have a variable which is a string of JSON, this JSON is an array of objects:

String actions = "[{'title': 'BBC', 'url': 'https://www.bbc.co.uk'}, {'title': 'GOOGLE', 'url': 'https://www.google.com'}]"

I need to convert this into some thing that I can use within my android app, so an array or object that I can iterate over. How would I go about this?

score 0 · Answer 1 · answered Sep 10 '18 at 12:08

You should use org.json.JSONArray for that.

String actions = "[{'title': 'BBC', 'url': 'https://www.bbc.co.uk'}, {'title': 'GOOGLE', 'url': 'https://www.google.com'}]" 

JSONArray actionArray = new JSONArray(actions)
for(int x = 0; x < actionArray.length; x++ ){
    JSONAobject obj = actionArray.getJSONObject(x);
    String title = obj.optString("title");
    //Other code
}

Bartek · Accepted Answer · 2018-09-10T12:15:02.420

0

Using Gson

String actions = "[{'title': 'BBC', 'url': 'https://www.bbc.co.uk'}, {'title': 'GOOGLE', 'url': 'https://www.google.com'}]";

List list = new Gson().fromJson(actions, List.class);

If your JSON has known structure you can map it to class, for example:

class Website {
        String title;
        String url;
}


Type type = new TypeToken<List<Website>>() {}.getType();
List<Website> list = new Gson().fromJson(actions, type);

edited Sep 10 '18 at 12:15

answered Sep 10 '18 at 12:09

Bartek

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Results in `java.lang.ArrayIndexOutOfBoundsException: length=0; index=0` error. – ChrisBratherton Sep 10 '18 at 14:11
What is your Gson version? Did you test above code for other input, than provided? – Bartek Sep 10 '18 at 14:16
The actual string that I am passing is: `[{"title":"GOOGLE","url":"https://www.google.com"}]` this comes from an API. My Gson version is 2.7 – ChrisBratherton Sep 10 '18 at 14:19
I checked code and it works in both scenarios, with version 2.7. Are you shure that "new Gson().fromJson(actions,..." throws exception? – Bartek Sep 10 '18 at 14:28
Oh, I take back everything I said, it looks as though it was my Log causing that error. – ChrisBratherton Sep 10 '18 at 14:33
This works, thanks :) – ChrisBratherton Sep 10 '18 at 14:34

score -1 · Answer 3 · answered Sep 10 '18 at 12:05

-1

In java, you can use json library for this purpose: https://mvnrepository.com/artifact/org.json/json

answered Sep 10 '18 at 12:05

G.G.

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There's not need for use external library because Java has buildin class for that. – michaelitoh Sep 10 '18 at 12:10
Cool. but that does not mean that my answer is incorrect. Why have you voted it down? – G.G. Sep 11 '18 at 02:36
i have not voted down – michaelitoh Sep 11 '18 at 02:39

Convert a string which contains an array of json objects to an array in Java

3 Answers3