Java 8 Method Reference - Method Reference on Instance Examples

public class ObjectRefExample {

    DataService dataService = new DataService();

    public static void main(String[] args) {

        ObjectRefExample example = new ObjectRefExample();
        example.showUsersInfo();
    }

    private void showUsersInfo() {
        List<String> userIds = dataService.getAllUserIds();
        //method ref on instance, using this
        userIds.forEach(this::displayUserInfo);
    }

    private void displayUserInfo(String id) {
        System.out.println("User Info for id :" + id);
        //method ref on dataService instance
        display(id, dataService::getUserNameById);
        display(id, dataService::getUserAddressById);
        System.out.println("------------------------");
    }

    private void display(String id, Function<String, ?> theConsumer) {
        System.out.println(theConsumer.apply(id));
    }
}