java - Jackson JSON: get node name from json-tree

Question

How can I receive the node names from a JSON tree using Jackson? The JSON-File looks something like this:

{  
    node1:"value1",
    node2:"value2",
    node3:{  
        node3.1:"value3.1",
        node3.2:"value3.2"
    }
}

I have

JsonNode rootNode = mapper.readTree(fileReader);

and need something like

for (JsonNode node : rootNode){
    if (node.getName().equals("foo"){
        //bar
  }
}

thanks.

Answer 1

For Jackson 2+ (com.fasterxml.jackson), the methods are little bit different:

Iterator<Entry<String, JsonNode>> nodes = rootNode.get("foo").fields();

while (nodes.hasNext()) {
  Map.Entry<String, JsonNode> entry = (Map.Entry<String, JsonNode>) nodes.next();

  logger.info("key --> " + entry.getKey() + " value-->" + entry.getValue());
}