From Eugene Tskhovrebov

List<MyClass> myObjects = Arrays.asList(mapper.readValue(json, MyClass[].class))

This solution seems to be the best for me.

You could define a wrapper class as following:

public class Wrapper {

    private List<String> values;

    // Default constructor, getters and setters omitted
}

Then use:

Wrapper wrapper = mapper.readValue(json, Wrapper.class);
List<String> values = wrapper.getValues();

If you want to avoid a wrapper class, try the following:

JsonNode valuesNode = mapper.readTree(json).get("values");

List<String> values = new ArrayList<>();
for (JsonNode node : valuesNode) {
    values.add(node.asText());
}

If you need to map the incoming json to your List you can do like this

String jsonString = ...; //Your incoming json string
ObjectMapper mapper = new ObjectMapper();
Class<?> clz = Class.forName(yourTypeString);
JavaType type = mapper.getTypeFactory().constructCollectionType(List.class, clz);
List <T> result = mapper.readValue(jsonString, type);

Edit

Something like this, completly untested and never done

public Message<T> deserialize(JsonParser jsonParser, DeserializationContext arg1)
    throws IOException, JsonProcessingException {
    ObjectMapper mapper = new ObjectMapper();
    ObjectCodec oc = jsonParser.getCodec();
    JsonNode node = oc.readTree(jsonParser);

    JsonNode timeStamp = node.get("time");
    Timestamp time = mapper.readValue(timeStamp, Timestamp.class);
    JsonNode restAction = node.get("action");
    RestAction action = mapper.readValue(restAction, RestAction.class);
    String type = node.get("type").getTextValue();
    Class<?> clz = Class.forName(type);
    JsonNode list = node.get("data");
    JavaType listType = mapper.getTypeFactory().constructCollectionType(List.class,   clz);
    List <T> data = mapper.readValue(list, listType);

    Message<T> message = new Message<T>;
    message.setTime(time);
    message.setAction(action);
    message.setType(type);
    message.setData(data);

    return message;
}

If you just want your mapper to read into a List<Long>, use this trick for obtaining full generics type information by sub-classing.

Example

ObjectMapper mapper = new ObjectMapper();
List<Long>listOfLong=mapper.readValue("[ 123421, 15643, 51243]" ,
                    new TypeReference<List<Long>>() {
                    });
System.out.println(listOfLong);

Prints

[123421, 15643, 51243]