Caching

Repeated expensive lookups, such as database reads, external API calls, or computed aggregates, benefit from an in-process cache. mangoo I/O wraps Caffeine and exposes an injectable Cache for the default application cache, plus named caches for when you need separate eviction policies or key spaces.

Entries expire after write (30 days by default). You can attach a fallback function so a get on a missing key loads and stores it automatically instead of returning null. Counter helpers cover rate limiting or metrics-style increments without needing a separate store.

Inject io.mangoo.cache.Cache for the application cache:

@Inject
private Cache cache;

cache.put("foo", "bar");
String value = cache.get("foo");
cache.remove("foo");
cache.clear();

Entries in the application cache expire 30 days after write (not after last access), and the cache holds at most 50 000 keys.

TTL and fallback

cache.put("foo", "bar", 10, ChronoUnit.MINUTES);
cache.put("foo", "bar", LocalDateTime.now().plusHours(1));

String value = cache.get("foo", key -> loadFromDatabase(key));
String timed = cache.get("foo", 5, ChronoUnit.MINUTES, key -> loadFromDatabase(key));

The fallback is a Function<String, Object>, and its result is stored under the same key so the next get hits the cache instead of the fallback.

cache.putAll(Map.of("a", 1, "b", 2));
Map<String, Object> batch = cache.getAll("a", "b");

Counters

cache.getAndIncrementCounter("logins");
cache.getAndDecrementCounter("logins");
cache.getCounter("logins");
cache.resetCounter("logins");

Named caches

The application cache is the default, but two more caches exist out of the box:

Name (CacheName)	Use	Eviction
APPLICATION	Default Cache injection	30 days after write, 50 000 keys
AUTH	Login lockout counters	60 minutes after write
BLACKLIST	Created only if authentication.blacklist is true	60 minutes after write

@Inject
public MyService(CacheProvider cacheProvider) {
    Cache auth = cacheProvider.getCache(CacheName.AUTH);
}

Register extra caches with cacheProvider.addCache(name, cache), and they show up on the admin dashboard alongside the built-in ones.