How to parse complex nested jsonarray tree in java

Pushpak :

I have a JSON array like this:

[{
  "name": "com",
  "children": [
    {
      "name": "project",
      "children": [
        {
          "name": "server"
        },
        {
          "name": "client",
          "children": [
            {
              "name": "util"
            }
          ]
        }
      ]
    }
  ]
}]

And I need all the names from all the JSON objects. Is there any way to get this done in java?

I want a recursive function.

My expected result is like :

[
    {name:"com"},
    {"name":"project"},
    {"name":"server"},
    {"name":"client"},
    {"name":"util"}]

noiaverbale :

This is a simple recursive function to get all names properties from your json array:

public static Collection<String> getAllNames(JSONArray jsonArray, List<String> names) {
    for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject object = jsonArray.getJSONObject(i);
        names.add(object.getString("name"));
        if (object.has("children")) {
            JSONArray children = object.getJSONArray("children");
            getAllNames(children, names);
        }
    }

    return names;
}

This will provide you a list of names that you can use to construct a new json array. A possible way is this:

 public static JSONArray getJsonArraysOfNames(List<String> names) {
    JSONArray jsonArray = new JSONArray();
    for (String name : names) {
        JSONObject object = new JSONObject();
        object.put("name", name);
        jsonArray.put(object);
    }

    return jsonArray;
}

UPDATE

If you prefer an all-in-one solution then you can go with this approach:

public static JSONArray getNames(JSONArray inputArray, JSONArray outputArray) {
    for (int i = 0; i < inputArray.length(); i++) {
        JSONObject inputObject = inputArray.getJSONObject(i);

        JSONObject outputObject = new JSONObject();
        outputObject.put("name", inputObject.getString("name"));
        outputArray.put(outputObject);

        if (inputObject.has("children")) {
            JSONArray children = inputObject.getJSONArray("children");
            getNames(children, outputArray);
        }
    }

    return outputArray;
}