What should I return if my cacheResolver found no cache to use?

Question

I'm using EhCache on a service's delegate with spring's annotations.

On my @Cacheable annotation I've added a resolverFactoryName field to resolve my cache at runtime.

Then I implement CacheableCacheResolver interface, and return a cache depending of business rules, but sometimes I have no cache to return according to these rules.

If I return null EhCache's lib gave me a NPE. What is the way to do when I've no cache to return and so the app should no cache any of these values ? Is there a "fake" cache to return? Is there something like a NoCacheException to throw?

Answer 1

I do not think exception is the way to go, you really want to return a no-op cache implementation.

From the class name you give - CacheableCacheResolver - it looks like you are using ehcache-spring-annotations which does not seem to have support for what you want - a no-op cache.

Note that you can still take care of it yourself.

If you were to use the Spring Caching abstraction, you could use a similar system which has support for no-op caches through org.springframework.cache.support.NoOpCacheManager.NoOpCache .