Resource adapters for the client

A resource adapter is a system-level software driver that a Java application uses to connect to an enterprise information system (EIS). A resource adapter plugs into an application client and provides connectivity between the EIS and the enterprise application.

Important: This topic is not relevant to the WebSphere MQ resource adapter. WebSphere MQ classes are picked up automatically by the client container (for both stand alone and with a WAS installation).

The resource adapter support for the Java EE client applications is a subset of the support for the server. For any resource adapter installed using the clientRAR tool, the client resource adapter is used in a non-managed environment and must conform to the Java EE Connector Architecture Specification Version 1.5 or higher. Only outbound connections to the EIS are supported through the ManagedConnectionFactory interfaces. The inbound messaging support (from the EIS), life cycle management, and work management aspects of the specification are not supported on the client.

For a client application to use a resource adapter, it must be installed in the directory specified by the environment variable, CLIENT_CONNECTOR_INSTALL_ROOT, defined when the setupCmdLine script runs. The launchClient tool, Application Client Resource Configuration Tool (ACRCT) and clientRAR tool all use this variable to find the default location of all installed resource adapters. To install a resource adapter in the client, use the clientRAR tool. Once the resource adapter is installed, it must be configured using the ACRCT. The client configuration tool adds the resource adapter configuration to the EAR file. Then, connection factories and administered objects are defined.

When running Java EE application clients, the launchClient script specifies a system property called com.ibm.ws.client.installedConnector, which is set to the same value as the CLIENT_CONNECTOR_INSTALL_ROOT variable. This is the default location for installed resource adapters and can be overridden for each launchClient call by specifying the -CCD parameter. When the client container is activated, all resource adapter subdirectories under the specified default location for the resource adapters directory are added to the classpath. This action allows the client application to use the resource adapters without using the ACRCT to specify any of the client resources.

Use resource adapters is a new mechanism for easily extending client applications.

Related concepts

Relational resource adapters and JCA

Related tasks

Use application clients