Server Access for J2EE support for J2EE Connector Architecture

In support of the J2EE Connector Architecture specification 1.0., IBM provides WebSphere InterChange Server Access for J2EE. With this product, you instantiate a WebSphere Access Resource Adapter (often called just an Access Resource Adapter) within your application component. This resource adapter provides J2EE application components access to WebSphere Interchange Server (ICS). InterChange Server is the component of the WebSphere business integration system that provides the ability to maintain business processes that involve multiple EISs.

Note:
For an overview of the features and capabilities of the WebSphere business integration system, see the Technical Introduction to IBM WebSphere InterChange Server.

The WebSphere Access Resource Adapter brings the following benefits to application components in a J2EE application:

The following situations are possible usage scenarios for Server Access for J2EE:

Server Access for J2EE provides support for the following standards of the J2EE Connector Architecture specification 1.0.:

Note:
IBM WebSphere InterChange Server Access for J2EE has been implemented in full accordance with the standards, as described in the J2EE Connector Architecture specification 1.0..

IBM WebSphere Access Resource Adapter

A WebSphere Access Resource Adapter enables an application component to access and use IBM WebSphere Business Integration Collaborations and other services. Collaborations represent business processes, which can involve multiple EISs. The WebSphere business integration solution initiates execution of a collaboration at the request of the Access Resource Adapter. The Access Resource Adapter sends data that represents the triggering event of a collaboration to the WebSphere business integration system solution, which in turn sends it to an ICS instance. Because these solutions are external to the WebSphere business integration system, their request for collaboration execution initiates a call-triggered flow. By requesting execution of collaborations, Access Resource Adapters can send and receive information in the ICS-managed EIS.

For an application component to communicate with a WebSphere Access Resource Adapter, Server Access for J2EE implements the CCI. To communicate with an ICS-managed EIS, an application component sends a request in the form of a CCI call to an Access Resource Adapter, which communicates with ICS to initiate the request. InterChange Server handles any communication with ICS-managed EISs through execution of the collaboration.

Figure 4 shows the WebSphere business integration system implementation of the J2EE connector architecture.

Figure 4. Access to an ICS-managed EIS through Server Access for J2EE

The figure shows a schematic of how and ICS-managed EIS can be accessed through Server Access for J2EE. The image is a flow diagram starting in the upper left with a horizontal arrow labelled: "Application component makes a CCI call" which terminates at a shaded rectangle, entitled: "WebSphere Access Resource Adapter". This rectangle contains 2 nodes: "CCI implementation" and "InterChange Server Access interface (client-side)". The incoming arrow terminates in the "CCI implementation node" and a new arrow begins in the "InterChange Server Access interface (client-side)" node. This horizontal arrow runs to the right and ends at a shaded cell representing the "WebSphere InterChange Server". This cell contains a single rectangle: "InterChange Server interface (Server-side)". An arrow runs from the "WebSphere InterChange Server" node downwards to a cell labelled "WebSphere Business Integration Adapter" and from here another arrow points down to a final cell: "EIS application".

As Figure 4 shows, communication with an ICS-managed EIS involves an application component sending a request to an Access Resource Adapter. The Access Resource Adapter communicates with ICS to initiate the request. ICS handles any communication with ICS-managed EISs by controlling execution of the collaboration. To provide this communication, the IBM WebSphere Server Access for J2EE product includes the following components:

The application component and Access Resource Adapter

For an application component to communicate with a WebSphere Access Resource Adapter, Server Access for J2EE implements the CCI. To communicate with an ICS-managed EIS, an application component sends a request in the form of a CCI call to an Access Resource Adapter, which communicates with ICS to initiate the request. InterChange Server handles any communication with ICS-managed EISs through execution of the collaboration.

Table 2 provides a summary of the tasks that an application component can request from an Access Resource Adapter.

Table 2. Server Access for J2EE implementation of CCI

Task of the application component CCI Interface For more information
Manage a connection to WebSphere InterChange Server ConnectionFactoryConnectionConnectionSpec "Managing the connection"
Send information to an InterChange Server-managed EIS InteractionInteractionSpec "Sending data to an ICS-managed EIS"
Represent data to send to and receive from the InterChange Server-managed EIS Record MappedRecordIndexedRecordRecordFactory "Using records"
Acquire metadata ConnectionMetaDataResourceAdapterMetaData "Obtaining metadata"
Handle exceptions ResourceException "Handling exceptions"

All interfaces listed in the CCI Interface column in Table 2 are part of the following Java package:

javax.resource.cci

All Server Access for J2EE implementations of these CCI interfaces are part of the Java package:

com.crossworlds.j2eeconnector

The Access Resource Adapter and InterChange Server

To communicate with an ICS-managed EIS, a J2EE component sends a request to the WebSphere Access Resource Adapter, which communicates with ICS to initiate the request. ICS handles any communication with ICS-managed EISs by controlling execution of the collaboration. To provide communication between the Access Resource Adapter and ICS, IBM provides WebSphere InterChange Server Access.

InterChange Server Access Interface is the low-level Java interface that enables external process (called access clients) to request execution of a collaboration. An Access Resource Adapter is an external process to the WebSphere business integration system and therefore uses InterChange Server Access to communicate with an instance of ICS. The Server Access Interface methods use CORBA-IIOP as the underlying transport mechanism. By isolating the calls to the Server Access Interface within an Access Resource Adapter, the application component does not have to contain ICS-specific code.

Server Access for J2EE provides implementations of the CCI interfaces that use methods of the Server Access Interface. This interface enables the Access Resource Adapter to support the application-component tasks in Table 2.. Figure 5 shows the structure of the communication between an Access Resource Adapter and ICS.

Figure 5. Access to an ICS-managed EIS

The figure shows a schematic of the access to an ICS-managed EIS. The figure is a flow diagram starting in the upper left with an arrow pointing right which is labelled "Application component requests information from an ICS-managed EIS". This arrow ends at a cell labelled "WebSphere Access Resource Adapter" the left half of which is shaded, the right half is labelled "InterChange Server Access interface". From this cell an arrow points right, labelled "CORBA-IIOP" which ends at a second cell denoted by "InterChange Server". The left half of this cell is labelled "InterChange Server Access interface" and the right half is shaded. From this cell an arrow points down to a cell labelled "WebSphere Business Integration Adapter" and from that cell an arrow points down to a cell denoted "EIS application".

Note:
For more information on the IBM WebSphere InterChange Server Access Interface, see the Access Development Guide.

System-level contracts

In a managed environment, the application server communicates with resource adapters to enable application components to obtain EIS information. For an application server to communicate with a WebSphere Access Resource Adapter, the resource adapter implements the system-level contracts that the J2EE Connector Architecture specification 1.0. defines. Table 3 shows the system-level contracts that IBM WebSphere InterChange Server Access for J2EE provides.

Table 3. System-level contracts supported by Server Access for J2EE

System-level contract Server Access for J2EE support
Connection management Yes
Security management Minimum
Transaction management No

However, you can achieve some transaction management through the use of transactional collaborations. For more information, see the Collaboration Development Guide.

Copyright IBM Corp. 1997, 2004