How to find node exists in JSON

Question

I have following JSON

{"subscription": 
 {
 "callbackReference": "xyz" ,
 "criteria": "Vote",
 "destinationAddress": "3456" ,
  "notificationFormat" : "JSON"
 }
}

I want to check whether "notificationFormat" elements exits there using JSONPath expression. I can get the value of above element using following JSONPath expression.

$.subscription.notificationFormat

Can I use similar kind of expression which returns boolean value checking whether elements exists ?

Answer 1

    ReadContext ctx = JsonPath.parse("{}", com.jayway.jsonpath.Configuration.defaultConfiguration().addOptions(Option.SUPPRESS_EXCEPTIONS));

    assertThat(ctx.read("$.components"), nullValue());

Answer 2

If I understood your question correct here is an answer.

This would check if notificationFormat exists in your json.

$.subscription[?(@.notificationFormat)]

That would get all destinationAddress in case if notificationFormat exists

$.subscription[?(@.notificationFormat)].destinationAddress