How to do it...

  1. Let's create a User class to be our cached object:
public class User {        private String name;    private String email;      //DO NOT FORGET TO IMPLEMENT THE GETTERS AND SETTERS}
  1. And then create a singleton to hold our user list cache:
@Singleton@Startuppublic class UserCacheBean {    protected Queue<User> cache = null;        @PersistenceContext    private EntityManager em;    public UserCacheBean() {    }    protected void loadCache() {        List<User> list = em.createQuery("SELECT u FROM USER                                          as u").getResultList();        list.forEach((user) -> {            cache.add(user);        });    }    @Lock(LockType.READ)    public List<User> get() {        return cache.stream().collect(Collectors.toList());    }    @PostConstruct    protected void init() {        cache = new ConcurrentLinkedQueue<>(); loadCache(); ...

Get Java EE 8 Cookbook now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial