Coherence for Java allows Java applications to access Coherence clustered services, including data, data events, and data processing from outside the Coherence cluster. Typical uses for Java extend clients include desktop and Web applications that require access to Coherence caches.
The Coherence for Java library connects to a Coherence*Extend clustered service instance running within the Coherence cluster using a high performance TCP/IP-based communication layer. This library sends all client requests to the Coherence*Extend clustered service which, in turn, responds to client requests by delegating to an actual Coherence clustered service (for example, a partitioned or replicated cache service).
Like cache clients that are members of the cluster, Java extend clients use the
CacheFactory.getCache() API call to retrieve a
NamedCache instance. After it is obtained, a client accesses the
NamedCache in the same way as it would if it were part of the Coherence cluster. The fact that
NamedCache operations are being sent to a remote cluster node (over TCP/IP) is completely transparent to the client application.
Unlike the C++ and .NET distributions, Java does not have a separate client distribution. The API delivered with Coherence for Java is the same API that is used to create extend clients. The API is detailed in the Oracle Coherence Developer's Guide and not duplicated in this guide. When building Java extend clients, refer to Part I, "Getting Started" in this guide (for basic setup) and Part IV, "Using the Programming API," in the Oracle Coherence Developer's Guide.