Using J2EE Architecture

Resource Adapter

A resource adapter is a system-level software driver used by an application server or client to connect to an enterprise system. A resource adapter plays a central role in the integration and connectivity between your enterprise system and an application server — it is the point of contact between application components, application servers, and enterprise information systems.

The JNDI name of the resource adapter is eis/BridgeAPI except for Oracle where it is BridgeAPI.

J2EE Stateful Session EJB

Session EJBs are efficient and lightweight Java beans that work well in J2EE environments. A JAR file is created, along with a resource adapter RAR file, when an EJB is generated as part of an enterprise application, and then it is deployed to your selected application server on a per project basis. Projects can contain multiple tasks.

The stateful session EJB (written to the Enterprise JavaBeans specification v2.0) exposes the BridgeAPI interface.

The JNDI name of the stateful session EJB is ejb/BridgeAPI except for Oracle where it is BridgeAPI_EJB.

BridgeAPI Architecture

The Services Builder for CICS 3270 Bridge stateful session EJBs meet the Enterprise JavaBeans Specification v. 2.0. Both the stateful session EJB and resource adapter contain the complete BridgeAPI interface. The EJB establishes a connection to the resource adapter, which makes and maintains the connection to the CICS 3270 Bridge in the CICS region on the host.

The Enterprise application (EAR) contains the stateful session EJB JAR along with a resource adapter RAR. After the enterprise application is deployed to the Application Server you can create Web applications to access the stateful session EJBs (this is the preferred method). You can also repackage the application to include your web applications.

architecture

Attachmate RA and EJB Requestors use the Java Naming and Directory Interface (JNDI) to deploy enterprise applications to your application server. The enterprise application uses both stateful session EJB and resource adapter functionality. The stateful session EJB accesses host data through the resource adapter.

RA and EJB Requestors

The Attachmate RA and EJB Requestors are generic resource adapters written to the Sun J2EE Connector Architecture Specification, version 1.0 implementing a custom interface containing methods based on the Attachmate QACOM API set, with extensions for the CICS Bridge and its capabilities. Because both the application servers and the Attachmate RA and EJB Requestors adhere to the industry-standard J2EE connector architecture, you are ensured of complete compatibility between the supported application servers and your enterprise system.

The RA and EJB Requestors install requires an install code and places 2 files in the install root directory:

BridgeAPI.ear is an enterprise application that can be deployed to application servers. For a list of supported application servers, see the System Requirements. The BridgeAPI.ear contains a resource adapter and a J2EE stateful session EJB.

Application server specific configuration setting are controlled through .xml files.

The BridgeAPI.ear may be accessed through a web application (WAR) or the Java client. Each WAR can be deployed on it own or repackaged inside the EAR.

For specific examples using the RA and EJB Requestors, see the supplied code samples for J2EE.

To use the resource adapter directly you must add the BridgeAPI-ra-client.jar file to the application server class path. For details, see Placing BridgeAPI-ra-client.jar in Application Server class path in the J2EE Sample Code: Accessing the Resource Adapter from a Web Application .

Code Samples for J2EE

Related Topics
Bullet Packaging Enterprise Applications
Bullet RA and EJB Requestor Errors
Bullet J2EE Sample Code: Accessing the Stateful Session EJB in a Web Application
Bullet J2EE Sample Code: Accessing the Resource Adapter from a Web Application
  Attachmate