Convert string to json doesn't work java

I have a problem with convert string to json. Namely, my json string is:

{"serverId":2,"deviceId":736,"analysisDate":"2017-05-11T07:20:27.713Z","eventType":"Logs","eventAttributes":[{"name":"level","value":"INFO"},{"name":"type","value":"Video Blocked On"},{"name":"cameraId","value":"722"},{"name":"userId","value":"1"}]}

My code:

    try {
        JSONObject object = new JSONObject(jsonString);
        JSONArray array = object.getJSONArray("eventAttributes");
        System.out.println("ARRAY: " + array);

        for (int i = 0; i < array.length(); i++) {
            JSONObject obj = new JSONObject(array.getJSONObject(i));
            System.out.println("OBJ: " + obj);

        }
    } catch (JSONException ex) {
        Exceptions.printStackTrace(ex);
    }

System.out.println array is: 

[{"name":"level","value":"INFO"},{"name":"type","value":"Video Blocked On"},{"name":"cameraId","value":"722"},{"name":"userId","value":"1"}]

but if I print obj is "{}", four times. So it is correct, because array has 4 elements, but why it is empty object? I'm using org.json.

Thanks

Jon Skeet
people
quotationmark

You're calling the JSONObject(Object) constructor, passing in a JSONObject (the element in the array). That constructor is documented as:

Construct a JSONObject from an Object using bean getters. It reflects on all of the public methods of the object. For each of the methods with no parameters and a name starting with "get" or "is" followed by an uppercase letter, the method is invoked, and a key and the value returned from the getter method are put into the new JSONObject. [...]

Now JSONObject itself doesn't have anything that fits a bean getter, so you end up with no keys. You don't want to treat the JSONObject as a bean.

That's why your current code doesn't work. To fix it, just don't call the constructor - instead, use the fact that the array element is already a JSONObject:

JSONObject obj = array.getJSONObject(i);

Output with that change:

OBJ: {"name":"level","value":"INFO"}
OBJ: {"name":"type","value":"Video Blocked On"}
OBJ: {"name":"cameraId","value":"722"}
OBJ: {"name":"userId","value":"1"}

people

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