Multiple Caffeine LoadingCaches added to Spring CaffeineCacheManager - spring

Question

I'm looking to add several distinct LoadingCache's to a Spring CacheManager, however I don't see how this is possible using CaffeineCacheManager. It appears that only a single loader is possible for refreshing content, however I need separate loaders for each cache. Is it possible to add multiple loading caches to a Spring cache manager? If so, then how?
CaffeineCacheManager cacheManage = new CaffeineCacheManager();
LoadingCache<String, Optional<Edition>> loadingCache1 =
Caffeine.newBuilder()
.maximumSize(150)
.refreshAfterWrite(5, TimeUnit.MINUTES)
.build(test -> this.testRepo.find(test));
LoadingCache<String, Optional<Edition>> loadingCache2 =
Caffeine.newBuilder()
.maximumSize(150)
.refreshAfterWrite(5, TimeUnit.MINUTES)
.build(test2 -> this.testRepo.find2(test2));
// How do I add to cache manager, and specify a name?

Answer 1

Yes it is possible. Since you need to fine tune every cache, you are probably better at defining them yourself. Back to your example, the next step would be:
SimpleCacheManager cacheManager = new SimpleCacheManager();
cacheManager.setCaches(Arrays.asList(
new CaffeineCache("first", loadingCache1),
new CaffeineCache("second", loadingCache2)));
And then you can use that as usual, e.g.
#Cacheable("first")
public Foo load(String id) { ... }
If you are using Spring Boot, you can just expose the individual cache as beans (so org.springframework.cache.Cache implementations) and we'll detect them and create a SimpleCacheManager automatically for you.
Note that this strategy allows you to use the cache abstraction with different implementations. first could be a caffeine cache and second a cache from another provider.

Answer 2

Having this class will allow you to use #Cacheable("cacheA") where you want as normal:
#EnableCaching
#Configuration
public class CacheConfiguration {
#Bean
public CacheManager cacheManager() {
CaffeineCacheManager manager = new CaffeineCacheManager();
manager.registerCustomCache("cacheA", defaultCache());
manager.registerCustomCache("cacheB", bigCache());
manager.registerCustomCache("cacheC", longCache());
// to avoid dynamic caches and be sure each name is assigned to a specific config (dynamic = false)
// throws error when tries to use a new cache
manager.setCacheNames(Collections.emptyList());
return manager;
}
private static Cache<Object, Object> defaultCache() {
return Caffeine.newBuilder()
.maximumSize(1000)
.expireAfterWrite(5, TimeUnit.MINUTES)
.build();
}
private static Cache<Object, Object> bigCache() {
return Caffeine.newBuilder()
.maximumSize(5000)
.expireAfterWrite(5, TimeUnit.MINUTES)
.build();
}
private static Cache<Object, Object> longCache() {
return Caffeine.newBuilder()
.maximumSize(1000)
.expireAfterWrite(1, TimeUnit.HOURS)
.build();
}
}

Answer 3

Thanks for #rado, this is improved version of his answer. This way we can configure the cache from application properties directly
cache:
specs:
big-cache:
expire-after: WRITE
timeout: 2h
max-size: 1000
long-cache:
expire-after: ACCESS
timeout: 30d
max-size: 100
We need a cache properties for this
#Data
#EnableConfigurationProperties
#Configuration
#ConfigurationProperties(prefix = "cache")
public class CacheProperties {
private static final int DEFAULT_CACHE_SIZE = 100;
private Map<String, CacheSpec> specs = new HashMap<>();
#Data
public static class CacheSpec {
private Duration timeout;
private Integer maxSize = DEFAULT_CACHE_SIZE;
private ExpireAfter expireAfter = ExpireAfter.WRITE;
}
enum ExpireAfter { WRITE, ACCESS }
}
And then we can configure directly from external config file
#EnableCaching
#Configuration
#RequiredArgsConstructor
public class CacheConfiguration {
private final CacheProperties cacheProperties;
#Bean
public CacheManager cacheManager() {
CaffeineCacheManager manager = new CaffeineCacheManager();
Map<String, CacheProperties.CacheSpec> specs = cacheProperties.getSpecs();
specs.keySet().forEach(cacheName -> {
CacheProperties.CacheSpec spec = specs.get(cacheName);
manager.registerCustomCache(cacheName, buildCache(spec));
});
// to avoid dynamic caches and be sure each name is assigned
// throws error when tries to use a new cache
manager.setCacheNames(Collections.emptyList());
return manager;
}
private Cache<Object, Object> buildCache(CacheProperties.CacheSpec cacheSpec) {
if (cacheSpec.getExpireAfter() == CacheProperties.ExpireAfter.ACCESS) {
return Caffeine.newBuilder()
.expireAfterAccess(cacheSpec.getTimeout())
.build();
}
return Caffeine.newBuilder()
.expireAfterWrite(cacheSpec.getTimeout())
.build();
}
}
Now you can use the cache with using cache name
#Cacheable(cacheNames = "big-cache", key = "{#key}", unless="#result == null")
public Object findByKeyFromBigCache(String key) {
// create the required object and return
}
#Cacheable(cacheNames = "long-cache", key = "{#key}", unless="#result == null")
public Object findByKeyFromLongCache(String key) {
// create the required object and return
}