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.

[     {         "givenName": "Jim",         "formattedName": "jimJackson",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mr",         "honorificSuffix": "none"     },     {         "givenName": "john",         "formattedName": "johnLasher",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mr",         "honorificSuffix": "none"     },     {         "givenName": "carlos",         "formattedName": "carlosAddner",         "familyName": null,         "middleName": "none",         "honorifiPrefix": "mr",         "honorificSuffix": "none"     },     {         "givenName": "lisa",         "formattedName": "lisaRay",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mrs",         "honorificSuffix": "none"     },     {         "givenName": "bradshaw",         "formattedName": "bradshawLion",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mr",         "honorificSuffix": "none"     },     {         "givenName": "phill",         "formattedName": "phillKane",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mr",         "honorificSuffix": "none"     },     {         "givenName": "Gabriel",         "formattedName": "gabrielMoosa",         "familyName": null,         "middleName": "none",         "honorificPrefix": "mr",         "honorificSuffix": "none"     } ] 

I want to remove the "familyName" and "middleName" from all the JSON nodes of the above array. Is there any way to achieve this?

Answer 1

I haven't tested this, but I think something like this would do what you want:

import org.codehaus.jackson.node.ObjectNode; // ... for (JsonNode personNode : rootNode) {     if (personNode instanceof ObjectNode) {         ObjectNode object = (ObjectNode) personNode;         object.remove("familyName");         object.remove("middleName");     } } 

You could also do this more efficiently using Jackon's raw parsing API, but the code would be a lot messier.

Answer 2

ObjectMapper of Jackson gives solution with only few steps.

Save the json data in a file say 'data.json'. Copy following the code into a function without import statements and invoke the function. The resulting JSON will be written into a new file 'data1.json'.

import java.io.File; import java.io.IOException;  import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ObjectNode; ObjectMapper objectMapper = new ObjectMapper();         JsonNode jsonNode = objectMapper.readTree(new File("data.json"));         for (JsonNode node : jsonNode) {             ((ObjectNode)node).remove("familyName");             ((ObjectNode)node).remove("middleName");         }         objectMapper.writeValue(new File("data1.json"), jsonNode);