isSerializeNullIsOn

false

Since the Gson provider serializes 'null' values of JSON properties and displays them by default, the Jackson provider has this OSGi configuration property to note whether 'null' values are to be serialized into JSON or not. By default it is set to 'false' because of the backward compatibility with the old REST Container used in previous versions (Wink). In order to achieve equal behaviour of the Gson/Jackson providers in terms with the REST API, this configuration property has to be set to 'true'.