WebSphere Application Server V8.5 Administration and Configuration Guide for the Full Profile

Chapter 10. Accessing EIS applications from WebSphere 385

 Common Client Interface (CCI) for EIS access

The CCI defines a standard client API through which a JEE component accesses the EIS.

This simplifies writing code to connect to an EIS data store.

The resource adapter provides connectivity between the EIS, the application server, and

the enterprise application through the CCI.

 Implements the standard Service Provider Interface (SPI)

The SPI integrates the transaction, security, and connection management facilities of an

application server (JCA Connection Manager) with those of a transactional resource

manager.

Multiple resource adapters (one resource adapter per type of EIS) can be plugged into an

application server. This capability enables application components deployed on the

application server to access the underlying EISs, as shown in Figure 10-1.

Figure 10-1 Common Client Interface API

10.2 WebSphere Application ServerJCA support

In WebSphere Application Server, two types of objects are configured for JCA support:

 Resource adapters

 Connection factories

The application using the resource adapter requests a connection from the connection factory

through a JNDI lookup. The application then uses the connection factory to get a connection

to the underlying EIS.

The role of the WebSphere administrator is to:

 Install and define the resource adapter

 Define one or more connection factories associated with the resource adapter

Resource Adapter

for the EIS Oracle

Provided by EIS vendor

or Third Party vendor

Resource Adapter

for the EIS CICS

Resource Adapter

for the EIS IMS

J2EE Server Runtime

Included with J2EE

J2EE

Component

J2EE

Component

J2EE

Component

Common

Client

Interface

API

EIS

(CICS)

EIS

(Oracle)

EIS

(IMS)

386 WebSphere Application Server V8.5 Administration and Configuration Guide for the Full Profile

10.2.1 Resource adapters

A WebSphere resource adapter administrative object represents the library that supplies

implementation code for connecting applications to a specific EIS, such as IBM CICS® or

SAP. Resource adapters are stored in a resource adapter archive (RAR) file, which is a Java

archive (JAR) file used to package a resource adapter for the connector architecture. The file

has a standard file extension of.rar.

A RAR file can contain the following elements:

 EIS-supplied resource adapter implementation code in the form of JAR files or other

executables, such as DLLs

 Utility classes

 Static documents, such as HTML files for developer documentation, which are not used for

run time

 J2C common client interfaces, such as cci.jar

 A deployment descriptor (ra.xml)

This deployment descriptor instructs the application server about how to use the resource

adapter in an application server environment. The deployment descriptor contains

information about the resource adapter, including security and transactional capabilities,

and the ManagedConnectionFactory class name. In version 1.0 and 1.5, this deployment

descriptor is

mandatory.

Prior to JCA 1.6, metadata was specified only in the deployment descriptor, but now you

can specify metadata using either a deployment descriptor or annotations. Metadata that

is specified in annotations is merged into the deployment descriptor of a RAR module

when it is updated. Annotation metadata is

not merged if the module is marked

metadata-complete in the deployment descriptor or if the module version is earlier than

JCA 1.6.

The RAR file or JCA resource adapter is provided by your EIS vendor.

Registering the resource adapter with the high-availability manager specifies that the

high-availability (HA) manager will manage the lifecycle of a JCA 1.5 or later resource adapter

in a cluster. This manager ensures that applications using resource adapters for inbound

communication remain highly available. Appropriate use of the HA capability options enable

you to set up an environment that can implement failover for inbound activity when a server

goes down.

WebSphere provides three JCA resource adapters:

 The WebSphere Relational Resource Adapter: Used to connect to relational databases

using JDBC. The WebSphere Relational Resource Adapter is installed and runs as part of

WebSphere Application Server and needs no further administration.

 The Resource Adapter for Java Message Service (JMS): Used by applications that

perform JMS or JCA messaging with the default messaging provider

 The WebSphere MQ resource adapter: Used by applications that perform JMS or JCA

messaging with the WebSphere MQ messaging provider.

10.2.2 Connection factories

The WebSphere connection factory administrative object represents the configuration of a

specific connection to the EIS supported by the resource adapter. The connection factory can

be thought of as a list holder for connection configuration properties.