How to modify JsonNode in Java?

I need to change a JSON attribute's value in Java, I can get the value properly but I couldn't modify the JSON.

here is the code below

  JsonNode blablas = mapper.readTree(parser).get("blablas");
    for (JsonNode jsonNode : blablas) {
        String elementId = jsonNode.get("element").asText();
        String value = jsonNode.get("value").asText();
        if (StringUtils.equalsIgnoreCase(elementId, "blabla")) {
            if(value != null && value.equals("YES")){
                 // I need to change the node to NO then save it into the JSON
            }
        }
    }

What is the best way to do this?

JsonNode is immutable and is intended for parse operation. However, it can be cast into ObjectNode (and ArrayNode) that allow mutations:

((ObjectNode)jsonNode).put("value", "NO");

For an array, you can use:

((ObjectNode)jsonNode).putArray("arrayName").add(object.ge‌​tValue());

Adding an answer as some others have upvoted in the comments of the accepted answer they are getting this exception when attempting to cast to ObjectNode (myself included):

Exception in thread "main" java.lang.ClassCastException: 
com.fasterxml.jackson.databind.node.TextNode cannot be cast to com.fasterxml.jackson.databind.node.ObjectNode

The solution is to get the 'parent' node, and perform a put, effectively replacing the entire node, regardless of original node type.

If you need to "modify" the node using the existing value of the node:

1. get the value/array of the JsonNode
2. Perform your modification on that value/array
3. Proceed to call put on the parent.

Code, where the goal is to modify subfield, which is the child node of NodeA and Node1:

JsonNode nodeParent = someNode.get("NodeA")
                .get("Node1");

// Manually modify value of 'subfield', can only be done using the parent.
((ObjectNode) nodeParent).put('subfield', "my-new-value-here");

Credits:

I got this inspiration from here, thanks to wassgreen@

I think you can just cast to ObjectNode and use put method. Like this

ObjectNode o = (ObjectNode) jsonNode; o.put("value", "NO");

The @Sharon-Ben-Asher answer is ok.

But in my case, for an array i have to use:

((ArrayNode) jsonNode).add("value");