ShiftOne Java Object Cache

What is this?

ShiftOne Java Object Cache is a Java library that implements several strict object caching policies, decorators that add behavior, and a light framework for configuring them for an application.

What does it mean that the caches are strict?

It's strict in that each cache enforces two limits in a very strict and predictable way.

What caching policies are supported?

What features are supported?

How is a cache obtained?

This cache implementation strives to abstract from an application, the concrete implementation and configuration of a cache. For this reason, cache's should be accessed exclusively using the "Cache" interface (cache policies are not public classes, so this is required).

Both caches and cache factories may be obtained from a cache configuration. A cache configuration allows mnemonic names to be associated with various cache and factory configurations.

If an application absolutely needs to programmatically set the max size and timeout of a cache, then a cache factory should be obtained from the config first, and used to create a cache.

CacheConfiguration config = new CacheConfiguration();
CacheFactory factory      = config.getCacheFactory("default");
Cache cache               = factory.newInstance(
                                "news.sports.football",
                                1000*60 * minutes, 500);

If an application's requirements allow, all properties of a cache may be externalized to the cache configuration. This approach is far more powerful (and recommended).

CacheConfiguration config = new CacheConfiguration();
Cache cache               = config.createConfiguredCache(
                                "news.sports.football");

How does this cache perform?

Performace depends a great deal on configuration, as well as how the cache is being used (size, hit frequency, etc). Benchmarking is a complex task, and it is extremely difficult (if not impossible) to make a claim that one cache is faster than another.

Why was this implemented?

JOCache was originally implemented as part of the ExQ project to support ResultSet caching. It was later split out for use by other projects. It was designed to cache large expensive database query results.