Caches Java Objects, local or remote (via Redis).

Use Maven or Gradle, e.g. add repository and dependency to build.gradle:

repositories {
  ...
  maven { url "https://jitpack.io" }
  ...
}

dependencies {
  ...
  implementation "com.github.io-0:caja:1.4.4"
  ...
}

A Cache Manager is the first step to acquire a cache. It holds all configurations beside types.

// All caches retrieved from this will be local caches with heap 100 items and ttl 1 second.
CacheManager cacheManager = new CacheManager();

// All caches retrieved from this will be local caches with heap 10 items and ttl 2 second.
CacheManager cacheManager = new CacheManager(new LocalCacheConfig().setHeap(10).setTtlInSeconds(2));

// All caches retrieved from this will be local caches with heap 100 items and ttl 1 second, with one exception:
// If the cache is called 'my cache', it's heap will be 5 items and it's ttl 2 seconds.
CacheManager cacheManager = new CacheManager(new CacheManagerConfig()
  .setCacheConfigurations(Map.of("my cache", new LocalCacheConfig().setHeap(5).setTtlInSeconds(2)))
);

// All caches retrieved from this will be remote caches with ttl 2 second.
CacheManager cacheManager = new CacheManager(
  new RemoteCacheConfig().setTtlInSeconds(2).setHost("redis://localhost:6379/0")
);

// All caches retrieved from this will be remote caches with ttl 1 second, with one exception:
// If the cache is called 'my cache', it will be remote with ttl 2 seconds.
CacheManager cacheManager = new CacheManager(new CacheManagerConfig()
  .setDefaultCacheConfiguration(new RemoteCacheConfig().setHost("redis://localhost:6379/0"))
  .setCacheConfigurations(Map.of("my cache", new RemoteCacheConfig()
    .setTtlInSeconds(2).setHost("redis://localhost:6379/0")
  ))
);

The second step is type binding. Each cache has a name and types for keys and values. For this example we choose simple types, but it is also possible to use more complex types (e.g. POJOs).

Cache<Integer, String> shortTermCache = 
  cacheManager.getAsSync("short term cache", Integer.class, String.class);

System.out.println(shortTermCache.containsKey(1)); // prints false
shortTermCache.put(2, "two");
System.out.println(shortTermCache.get(2)); // prints 'two'
System.out.println(shortTermCache.getThrough(2, () -> "three")); // prints 'two', after
// ttl expires it would print 'three' and populate the cache

It is also possible to interact with caches in an async manner.

Cache<Integer, String> shortTermCacheAsync = 
  cacheManager.getAsAsync("short term cache", Integer.class, String.class);

System.out.println(await(shortTermCacheAsync.get(2))); // prints 'two', same 
// cache with async interface

Working with Collections or other types with sub types as values requires casting.

Cache<Integer, List<String>> aCache = (Cache<Integer, List<String>>)(Cache<Integer, ?>)
  cacheManager.getAsSync("a-cache", Integer.class, List.class, String.class);

aCache.put(1, List.of("one", "eins", "一"));
System.out.println(aCache.get(1)); // prints '[one, eins, 一]'

Remote caches require a running redis instance. For testing this can be easily archived with e.g. docker compose:

docker compose up

If no configuration is given, the CacheManager defaults to LocalCacheConfig for all caches. If a LocalCacheConfig or RemoteCacheConfig is provided via CacheManager constructor, it is set as default config and used for all caches. One can overwrite default config by providing name specific configuration via CacheManagerConfig in CacheManager constructor. One can overwrite default config by providing a new default as cacheManager.getAs* parameter. This parameter will be ignored if a matching named config exists.

1. CacheManager constructor CacheManagerConfig matching named CacheConfig (optional)
2. cacheManager.getAs* parameter CacheConfig (optional)
3. CacheManager constructor CacheManagerConfig DefaultCacheConfig (optional)
4. LocalCacheConfig

• ttlInSeconds (default 1): Time to live for all cached items in seconds
• logStatistics (default LogLevel.DEBUG): Log cache hits, misses, etc. at configured level
• heap (default 100): Number of maximum items cached

• ttlInSeconds (default 1): Time to live for all cached items in seconds
• logStatistics (default LogLevel.DEBUG): Log cache hits, misses, etc. at configured level
• host (default "redis://localhost:6379/0"): Location of remote cache. Redis supports auto discovery. In case of a standalone Master/Replica setup, by providing one host (master or replica), the other nodes which belong to the Master/Replica setup will automatically be discovered and used for connections. Furthermore, it is possible to connect to a Redis sentinel setup, for example with "redis-sentinel://localhost:26379,localhost:26380/0#mymaster".
• readFrom (default UPSTREAM): Defines in a Master/Replica setup from which Nodes data is read