title: How to check on field in JSON for null?
body: <p>I have below JSON response in which I need to check whether <code>response</code> field has null value or not. If <code>response</code> field has null value then I need to exit out of the program.</p>
  
  <pre><code>[
      {
          "results": {
              "response": null,
              "type": "ABC"
          },
          "error": null
      }
  ]
  </code></pre>
  
  <p>What is the easiest way to check this out? One option I know is to convert JSON to POJO and then check response field. Is there any other way? </p>