How do I extract the "extract" attribute from JSON?

Question

I am trying read JSON data from this link.

I am able to read the entire data inside pages attribute using :

JSONObject data=(JSONObject)new JSONTokener(IOUtils.toString(new URL("https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts&exintro=&explaintext=&titles=Russell%27s_paradox"))).nextValue();
String pageName=data.getJSONObject("query").getString("pages");
System.out.println(pageName);

I want to get the data from "extract" attribute next from the above mentioned link, which I am unable to. I am new with this and I can't find any resources to learn this.

I tried the following code but I am getting a JSONException.

JSONArray arr=data.getJSONArray("pages");
for(int i=0;i<arr.length();i++){
String def=arr.getJSONObject(i).getString("extract");
System.out.println(def);
}

Help.

Answer 1

The structure of the JSON you're trying to parse is this:

{
  "batchcomplete": "",
  "query": {
    "normalized": [
      {
        "from": "Russell's_paradox",
        "to": "Russell's paradox"
      }
    ],
    "pages": {
      "46095": {
        "pageid": 46095,
        "ns": 0,
        "title": "Russell's paradox",
        "extract": "..."
      }

That is, pages inside query is an object, not an array. And then, extract is within another nested object, with key 46095. You can get to the extract field like this:

JSONObject pages = data.getJSONObject("query").getJSONObject("pages");
for (String key : pages.keySet()) {
    String def = pages.getJSONObject(key).getString("extract");
    System.out.println(def);
}