8.2 JDO and the J2EE Connector Architecture

Although the J2EE Connector Architecture was principally designed as a standard mechanism to plug an EIS into an Application Server, it also provides a convenient mechanism for a JDO implementation to do likewise. As such, any JDO implementation designed to work within the J2EE environment likely provides a J2EE Connector Architecture resource adapter. This resource adapter means that J2EE applications can use JDO, because the JDO implementation collaborates with the Application Server on security, connection, and transaction management as defined by the J2EE Connector Architecture specification.

In the same manner that a J2EE application can use JDBC today and benefit from container-managed connections and transactions, via the J2EE Connector Architecture, an application using JDO gets the same benefits. So even though JDO is not officially part of the J2EE specification, it can still leverage the enterprise services offered by the J2EE environment.

Support for the J2EE Connector Architecture

The JDO specification does not actually require a JDO implementation to provide a J2EE Connector Architecture resource adapter. Therefore, a developer wishing to use JDO within the J2EE environment should ensure that the chosen JDO implementation does indeed support the J2EE Connector Architecture.

A JDO implementation is primarily interested in implementing the J2EE Connector Architecture system-level contracts because these allow it to collaborate with an Application Server. The J2EE Connector Architecture CCI is not of particular relevance to JDO, because JDO is itself the "client" API. The only CCI APIs of relevance to JDO are those involved with connections. The CCI defines two interfaces related to connection management: ConnectionFactory and Connection (which are covered later in this chapter).