title: Java - JSON Null Exception
body: <p>I'm using JSON to deserialize an input string that contains a <code>null</code> value for certain hashmap property. Does anyone have any clue why this exception occurs ? Is it possible that <code>null</code> is not accepted as a value Is this configurable somehow ?</p>
  
  <p>input sample:</p>
  
  <pre><code>{"prop1":"val1", "prop2":123, "prop3":null}
  </code></pre>
  
  <p>stacktrace:</p>
  
  <pre><code>net.sf.json.JSONException: null object
      at net.sf.json.JSONObject.verifyIsNull(JSONObject.java:2856)
      at net.sf.json.JSONObject.isEmpty(JSONObject.java:2212)
  </code></pre>
  
  <p>Thanks.</p>