Jackson Json accesing JsonNode property name

Question

I have a schema like this:

{
  "type" : "object",
  "$schema" : "http://json-schema.org/draft-03/schema#",
  "id" : "urn:jsonschema:com:vlashel:dto:UserDto",
  "description" : "this is the top description",
  "title" : "this is the top title",
  "properties" : {
    "number" : {
      "type" : "integer"
      "required" : true
    },
    "password" : {
      "type" : "string"
      "required" : true

    }
}

I have the following code that converts this shcema draft 3 to draft 4 by removing "required", I want to collect nodes property names that have 'requred' in them. How do I do that? I don't see methods for this..

             JsonNode jsonNode = jsonNodeIterator.next();
            ObjectNode element;
            if (jsonNode instanceof ObjectNode) {
                element = (ObjectNode) jsonNode;
                element.remove("required");
               String propertyName = element.getPropertyName(); //I'm looking for this kind of method.

Thanks!

Answer 1

You can get all of the nodes that have that property by using the List<JsonNode> findParents(String fieldName), which does that this for you. From the docs:

Method for finding a JSON Object that contains specified field, within this node or its descendants. If no matching field is found in this node or its descendants, returns null.

I made a quick example but had to add a few characters to the JSON blob you posted as it is missing some commas and a bracket and can't be read by the ObjectMapper. It is as simple as this:

JsonNode root = mapper.readTree(SCHEMA);
List<JsonNode> required = root.findParents("required");
for (JsonNode node: required) {
    Object prettyOutput = mapper.readValue(node, Object.class);
    System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(prettyOutput));
}

Output:

{
  "type" : "integer",
  "required" : true
}
{
  "type" : "string",
  "required" : true
}