CacheLoader

GuavaCacheLoader

public class TestCacheLoader extends CacheLoader<String, Boolean> {

    @Autowired
    private AuthUserManager userManager;

    @Override
    public AuthUser load(String key) throws Exception {
        return userManager.getUser(key);
    }
}

TwoFactorCodeManager.java

@Component
public class TwoFactorCodeManager {

    @Autowired
    private TwoFactorCacheLoader cacheLoader;
    private LoadingCache<String, Boolean> hasLinkList;

    @PostConstruct
    void init() {
        hasLinkList = CacheBuilder.newBuilder()
                .maximumSize(100)
                .expireAfterWrite(1, TimeUnit.HOURS)
                .build(cacheLoader);
    }

    public boolean hasLink(String userId) throws ExecutionException {
        return hasLinkList.get(userId);
    }

    public void remove(String userId) {
        hasLinkList.invalidate(userId);
    }

    public void removeAll() {
        hasLinkList.invalidateAll();
    }


}