如何在JsonNode中删除空节点

Question

i have some json, like this:

String str = "{\"menu\":[{\"form1\":\"nameForm1\"}, {\"form2\":\"nameForm2\"}]}";
ObjectMapper objectMapper = new ObjectMapper();
JsonNode testNode = objectMapper.readTree(str);

After some actions, I modified my json. for example

Iterator<Map.Entry<String, JsonNode>> fieldIterator = testNode.fields();
while (fieldIterator.hasNext()) {
    Map.Entry<String, JsonNode> entry = fieldIterator.next();
    if (entry.getValue().isArray()){
        for (JsonNode arrayNode : entry.getValue()){
            if (arrayNode.path("form2").isMissingNode()) {
                ((ObjectNode) arrayNode).removeAll();
           }
        }
    }
}

And my json began to look like:

{"menu":[{},{"form2":"nameForm2"}]}

How can I get json without empty array elements, ie

{"menu":[{"form2":"nameForm2"}]}

Answer 1

As I pointed in comment you need to remove arrayNode variable(which must be named as arrayElementNode ) from arrayNode(which is entry.getValue()), currently you are just removing arrayNode's(arrayElementNode's) properties

Here is the code with this logic

Iterator<Map.Entry<String, JsonNode>> fieldIterator = testNode.
while (fieldIterator.hasNext()) 
{
   Map.Entry<String, JsonNode> entry = fieldIterator.next();
   if (entry.getValue().isArray())
   {
      ArrayNode arrayNode = (ArrayNode) entry.getValue();
      for(int i = arrayNode.size()-1; i >= 0 ; i--)
      {
         if(arrayNode.get(i).path("form2").isMissingNode())
            arrayNode.remove(i);

     }
   }
}