JOnAS and the Connector Architecture

  1. Target Audience and Rationale
  2. Introducing the Connector Architecture
  3. Using a JCA Resource Adapter with JOnAS

Target Audience and Rationale

This chapter is dedicated to advanced JOnAS users concerned by EAI (Enterprise Application Integration). The Java Connector Architecture (JCA) defines a way for enterprise applications (based on EJB, servlet, JSP or J2EE clients) to communicate with external existing Enterprise Information Systems (EIS). This requires the use of a third party software component called "Resource Adapter", provided for a kind of EIS, and which should be previously deployed on the application server. In the case of JOnAS as application server, this chapter describes the way such a Resource Adapter should be deployed, and how an EJB application may use it. As JOnAS currently provides only an EJB container, only the EJB components of an enterprise application may access an EIS through a JCA Resource Adapter; JSP, Servlets or EJB clients are currently not concerned.

Introducing the Connector Architecture

The Java Connector Architecture allows the connection of different Enterprise Information Systems (EIS) to an application server such as JOnAS. It is based on the Resource Adapter (RA), an architecture component comparable to a software driver, connecting the EIS, the application server, and the enterprise application (EJB components in the case of JOnAS as application server). The RA is generally provided by an EIS vendor, and provides an interface (the Common Client Interface or CCI) to the enterprise application (EJBs) for accessing the EIS. The RA also provides standard interfaces for being plugged to the application server, so that they can collaborate to keep all system-level mechanisms (transactions, security, and connection management) transparent from the application components.

JCA Architecture

The resource adapter plugs into JOnAS and provides connectivity between the EIS, JOnAS, and the EJB application. The application performs "business logic" operations on the EIS data using the RA client API (CCI), while transactions, connections (including pooling) and security on the EIS is managed by JOnAS through the RA (system contract).

Using a JCA Resource Adapter with JOnAS

The following steps are involved for using a JCA Resource Adapter with JOnAS