You need to use an ObjectMapper:

ObjectMapper mapper = new ObjectMapper();
JsonFactory factory = mapper.getJsonFactory(); // since 2.1 use mapper.getFactory() instead
JsonParser jp = factory.createJsonParser("{\"k1\":\"v1\"}");
JsonNode actualObj = mapper.readTree(jp);

Further documentation about creating parsers can be found here.

If an Iterator is more useful...

...you can also use the elements() method of ArrayNode. Example see below.

sample.json

Copy{
    "first": [
        "Some string ...",
        "Some string ..."
    ],
    "second": [
        "Some string ..."
    ]
}

So, the List<String> is inside one of the JsonNodes.

Java

When you convert that inner node to an ArrayNode you can use the elements() method, which returns an Iterator of JsonNodes.

CopyFile file = new File("src/test/resources/sample.json");
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonNode = mapper.readTree(file);
ArrayNode arrayNode = (ArrayNode) jsonNode.get("first");
Iterator<JsonNode> itr = arrayNode.elements();
// and to get the string from one of the elements, use for example...
itr.next().asText();

New to Jackson Object Mapper?

I like this tutorial: https://www.baeldung.com/jackson-object-mapper-tutorial

Update:

You can also use .iterator() method of ArrayNode. It is the same:

Same as calling .elements(); implemented so that convenience "for-each" loop can be used for looping over elements of JSON Array constructs.

from the javadocs of com.fasterxml.jackson.core:jackson-databind:2.11.0