Using the Cache

Caching data is a typical optimization in modern applications, and so Wisdom provides a global cache. An important point about the cache is that it behaves just like a cache should: the data you just stored may just go missing.

For any data stored in the cache, a regeneration strategy needs to be put into place in case the data goes missing. This philosophy is one of the fundamentals behind Wisdom, and is different from Java EE, where the session is expected to retain values throughout its lifetime.

The default cache service uses EHCache and it’s enabled by default. You can also provide your own implementation via a service.

Accessing the Cache Service

The cache is available as a service, so accessible using:

include::{sourcedir}/controllers/cache/CacheUsage.java[tags=cache]

Note	The API is intentionally minimal to allow various implementations to be implemented.

Using this simple API you can store data in the cache:

include::{sourcedir}/controllers/cache/CacheUsage.java[tags=cache-set]

You can retrieve the data later:

include::{sourcedir}/controllers/cache/CacheUsage.java[tags=cache-get]

To remove an item from the cache use the remove method:

include::{sourcedir}/controllers/cache/CacheUsage.java[tags=cache-remove]

Caching HTTP responses

You can easily create an augmented cached action using standard action interception. Wisdom provides a default built-in interceptor for the standard case:

include::{sourcedir}/controllers/cache/CachedController.java[tags=cached-action]

Note	if the duration is not specified, the result is cached for one year.