Read the whole series on the JCA:
The emerging JCA standard provides a mechanism to store and retrieve enterprise data in J2EE (Java 2 Platform, Enterprise Edition). The latest versions of many application servers, including BEA's WebLogic and IBM's WebSphere, support JCA adapters for enterprise connectivity. Using JCA to access an EIS is akin to using JDBC (Java Database Connectivity) to access a database.
Before JCA, each EAI vendor created a proprietary resource adapter interface for its own EAI product, requiring a resource adapter to be developed for each EAI vendor and EIS combination (for instance you'd need a SAP resource adapter for Vitria and a SAP resource adapter for Tibco). To solve that problem, as one of its main thrusts, JCA attempts to standardize the resource adapter interfaces.
In this article, I first deliver a high-level introduction into the JCA. Then I discuss how JCA fits into an integration strategy. After that I compare JCA to EAI vendors' products. Finally, I discuss the limitations of the current JCA platform, followed by what the future may hold.
With that background in mind, let's consider how the current version of the JCA specification -- as well as J2EE in general -- measure up to some of the features found in EAI vendors' products.
Many EAI vendors, Vitria and Tibco for example, have either announced JCA support, or are in the process of releasing products that incorporate JCA-based adapters. Because the JCA 1.0 specification was finalized in July 2001, don't expect JCA in its initial release to match feature for feature to an EAI vendor's product, nor is that the aim. (Many features of the J2EE platform also compare to features in many EAI products.)
In light of this, and before we can discuss how JCA fits into the EAI picture, it's important to first understand some basic EAI features:
Let's look at each.
Most EAI vendors include proprietary adapters built to work with their products. Most proprietary adapters allow for synchronous and asynchronous communication to an EIS. JCA adapters closely resemble those adapters, except JCA adapters include only a synchronous communication channel. Resource adapters represent the EAI feature JCA most directly matches, although most EAI vendors' adapters offer a larger feature set (for instance asynchronous capability) than JCA adapters.