title: How do I parse a JSONObject into a list of integers?
body: <p>I have a json file like this.</p>
  
  <pre><code>    {
          "student": [
              {
                  "name": "takeru",
                  "id": 23,
              },
              {
                  "name": "george",
                  "id": 43,
              },
              {
                  "name": "hans",
                  "id": 45,
              }
          ],
          "cost": 100,
          "month": 6
      }
  </code></pre>
  
  <p>What I want to do is storing all student id's in a ArrayList?</p>