Coverting JSON String which is part of JSON object to JSON Object on the run

I am consuming a REST web services using REST template in my project which retus a JSON as below:

{"data": [{
        "id": "INT-1468819244684-event-no-97",
        "object1": {
            "JSONString": "{"object2":[{"object3":"value3","object4":"value4"}]}"
        }
    }]

}

While consuming the above JSON response I am able to create a bean class and able to dump JSON object/values into the same.

But the problem is above json response contains a string as below:

"JSONString": "{"object2":[{"object3":"value3","object4":"value4"}]}"

which is actually a json. So I have a bean in which I can fetch JSONString as String. But I want to somehow convert this String JSON to JSON Object at run time only when other objects are created and dump all its content in the same bean so that application should be ready to use its content.

Please guide me how to do the same.