7.2. SPI Interfaces

In addition to Cache and Node interfaces, JBoss Cache exposes more powerful CacheSPI and NodeSPI interfaces, which offer more control over the internals of JBoss Cache. These interfaces are not intended for general use, but are designed for people who wish to extend and enhance JBoss Cache, or write custom Interceptor or CacheLoader instances.

The CacheSPI interface cannot be created, but is injected into Interceptor and CacheLoader implementations by the setCache(CacheSPI cache) methods on these interfaces. CacheSPI extends Cache so all the functionality of the basic API is also available.

Similarly, a NodeSPI interface cannot be created. Instead, one is obtained by performing operations on CacheSPI, obtained as above. For example, Cache.getRoot() : Node is overridden as CacheSPI.getRoot() : NodeSPI.

It is important to note that directly casting a Cache or Node to its SPI counterpart is not recommended and is bad practice, since the inheritance of interfaces it is not a contract that is guaranteed to be upheld moving forward. The exposed public APIs, on the other hand, is guaranteed to be upheld.