Removing JSON elements with jackson

Question

I\'ve a particular JSON Node that corresponds to import org.codehaus.jackson.JsonNode, and not import org.codehaus.jackson.map.JsonNode.

[
    {
        \"g         


        

Answer 1

I recently came to this question because I had an unusual piece of JSON that I needed to remove an element of:

{
   "allan": { "score": 88 },
   "bill": { "score": 75 },
   "cassie": { "score": 96 },
   "warnings": [ { "name": "class_low_numbers", "message": "this class is has less than 10 students" }]
}

The first three elements represent a person and a respective score object. The last one "warnings", didn't match the score object and that's the one I wanted to remove.

Taking the rootNode as the starting JsonNode from gsteff's answer above, the way I found to remove this was to iterate through each of the nodes, adding an object mapped version of the node to a HashMap which was the desired return object that I wanted unless it was the "warnings" element:

HashMap results = new HashMap();

ObjectMapper mapper = new ObjectMapper();
mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

Iterator> fields = rootNode.fields();
while (fields.hasNext()) {
  Map.Entry next = fields.next();
  if (!next.getKey().equals("warnings")) {
    results.put(
        next.getKey(), mapper.treeToValue(next.getValue(), ScoreDetails.class));
  }
}

return results;