Spring cache vs. cachemanger
Spring framework recently introduced caching abstraction with org.springframework.cache.CacheManager central interface. This interface has few built-in implementations, including:
ConcurrentMapCacheManagerEhCacheCacheManagerNoOpCacheManagerSimpleCacheManager
This design allows you to switch caching library without touching application code. As you can see one of these built-in implementations is backed by EhCache. However notice that EhCacheCacheManager is just a bridge between Spring caching abstraction and EhCache library. Thus it needs existing net.sf.ehcache.CacheManager. You can either create an instance of this cache manager yourself or take advantage of existing factory bean, namely EhCacheManagerFactoryBean.
I understand it's confusing because of overlapping names, but it should be clear from the above which classes come from which library and why are they used.