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BEA WebLogic Java Adapter for Mainframe Introduction

Businesses around the world are using BEA WebLogic Server to deploy Java-based e-commerce applications. These applications support a wide range of business transactions, such as processing secure, online financial transactions. As the complexity of web-based applications evolve, the business transactions that these applications support may require integration with IBM mainframe applications. Storing up transactions for the mainframe and executing them periodically in batch mode is not sufficient.

BEA WebLogic Java Adapter for Mainframe (JAM) provides bidirectional, online request-response integration between Java applications running in a WebLogic Server environment and IBM Customer Information Control System (CICS) applications or Information Management System (IMS) applications.

BEA WebLogic Java Adapter for Mainframe Components

BEA WebLogic Java Adapter for Mainframe (JAM) is a set of components that provides seamless bidirectional interactions between Java applications running on a WebLogic Server platform and either CICS applications or IMS applications running on a mainframe. JAM allows EJBs, servlets, and stand-alone clients on WebLogic Server to initiate online requests to CICS or IMS programs and allows CICS or IMS programs to initiate online requests to EJBs on WebLogic Server.

The BEA WebLogic Java Adapter for Mainframe consists of two components:

- JAM gateway

- Communication Resource Manager (CRM)

The following utilities assist with JAM administration:

- CRM Monitor

- JAM Administration Servlet

The following application implementation utilities can be used with JAM:

- eGen COBOL Code Generator

- JAM Plug-in for WebLogic Process Integrator (If you are using JAM with BEA WebLogic Process Integrator)

Note: WebLogic Server is required, and a third-party SNA stack is required if the CRM is not installed on a mainframe. This third-party SNA stack must be installed on the same machine as the CRM. These required applications are sold separately.

JAM Gateway

The JAM gateway provides access into and out of the WebLogic Server environment. The JAM gateway is a component that runs in a WebLogic Server instance. The JAM gateway processes WebLogic Server-to-mainframe requests and responses in conjunction with the Communication Resource Manager (CRM). Requests coming from the mainframe are mapped to an EJB that services the request, while requests going to the mainframe are mapped to a mainframe program that can be executed using a CICS Distributed Program Link (DPL) or started from an IMS queue.

Communication Resource Manager

The Communication Resource Manager (CRM) is the software component of BEA WebLogic Java Adapter for Mainframe that prepares and receives messages over SNA connections to and from the mainframe.

The CRM runs as a separate native process. It enables APPC conversations and DPL protocols to flow into and out of the WebLogic Server environment. The CRM supports non-transactional IMS programs using the implicit APPC support for IMS. Many IMS programs that send messages to and receive messages from the IMS message queue can be used without change as either a client or a server.

The CRM can be distributed to the mainframe as an MVS APPC application or run on the same UNIX or Windows NT machine as WebLogic Server. The CRM may also be distributed to another UNIX or Windows NT machine, separate from the WebLogic Server machine. These three JAM configurations are described and illustrated in the BEA WebLogic Java Adapter for Mainframe Installation Guide. The CRM obtains its configuration from the JAM gateway. The JAM gateway reads this configuration information from the JAM gateway configuration file (jcrmgw.cfg).

For more detailed information on configuring JAM, refer to the BEA Java Adapter for Mainframe Configuration and Administration Guide.

CRM Monitor

The CRM Monitor is a utility that allows system managers to connect to and monitor the CRM server. The system managers can use the CRM Monitor to monitor link status and activity. They can also start and stop diagnostic tracing of the CRM server. This application can be installed on the platforms listed in the BEA Java Adapter for Mainframe Release Notes. For more detailed information, refer to the BEA Java Adapter for Mainframe Configuration and Administration Guide.

JAM Admin Servlet

The JAM Admin Servlet allows you to start and stop the JAM gateway when the system requires administration or maintenance but you do not want to stop or restart your WebLogic Server. For more detailed information, refer to the BEA Java Adapter for Mainframe Configuration and Administration Guide.

eGen COBOL Code Generator

The eGen COBOL Code Generator, also known as the eGen utility, is installed with the JAM gateway. It generates Java applications from a COBOL copybook and other mainframe application information. The generated application is dependent on the generation model chosen. The available generation models are as follows:

- Servlet only

- Client EJB (with optional servlet)

- Server EJB

- Java Class

The eGen utility generates a Java application by processing an eGen script. DataView Java code is generated from the first section of the script. This DataView code is used by the actual application code to provide data access and conversions as well as perform other miscellaneous functions. The actual application code is generated from the second section of the eGen script. For examples and instructions for the eGen COBOL Code Generator, refer to the BEA WebLogic Java Adapter for Mainframe Programming Guide and BEA WebLogic Java Adapter for Mainframe Scenarios Guide.

Example applications corresponding to each of the four generation models can be generated using the eGen utility. These scripts can be found in the samples.jar file. The samples.jar file can be found in the <JAM_HOME>\examples directory. The applications generated from these scripts are used as examples throughout the BEA Java Adapter for Mainframe Programming Guide and BEA Java Adapter for Mainframe Scenarios Guide.

JAM Plug-in for WebLogic Process Integrator

The JAM Plug-in for WebLogic Process Integrator allows you to add mainframe actions to perform in your WebLogic Process Integrator workflows. Mainframe actions allow you to send mainframe requests from WebLogic Process Integrator workflows to Customer Information Control System (CICS) applications or Information Management System (IMS) applications running on a mainframe. The JAM Plug-in also allows you to initiate WebLogic Process Integrator workflows from CICS or IMS application requests. To use this plug-in, JAM, WebLogic Process Integrator, and BEA WebLogic XML/Non-XML Translator must be installed before you install JAM. Also, you must have a working knowledge of WebLogic Process Integrator and WebLogic XML/Non-XML Translator. For information on using JAM with WebLogic Process Integrator and WebLogic XML/Non-XML Translator, see the BEA Java Adapter for Mainframe Workflow Processing Guide.

Note: WebLogic Process Integrator and the WebLogic XML/Non-XML Translator are available only as part of BEA WebLogic Integration.

About BEA WebLogic Java Adapter for Mainframe

The "BEA WebLogic Java Adapter for Mainframe Components" section describes how the BEA WebLogic Java Adapter for Mainframe components work individually. This section describes how those components work together. As illustrated in Figure 1, BEA WebLogic Java Adapter for Mainframe connects WebLogic Server and mainframe environments. The JAM gateway is a Java application that runs in WebLogic Server and can be called from Java applications running in WebLogic Server.

Figure 1 JAM Connecting WebLogic Server and Mainframe

This release of the WebLogic Java Adapter for Mainframe product includes the following features:

- Support for WebLogic Server clustering

- Access to Legacy Systems through WebLogic Server

- Workflow Processing using WebLogic Process Integrator and WebLogic XML/Non-XML Translator

Providing Clustering with WebLogic Server

Clustering involves the use of two or more replicated servers to ensure fast, continuous service to users and provide the benefits of scalability and high-availability. Clustering capabilities for JAM are provided through the WebLogic Server configuration. The JAM gateway can work with your cluster to provide scalability through automated load balancing across replicas. However, high-availability through automated failover across replicas is not available because the gateway communicates with the Communications Resource Manager (CRM) in a remote environment that does not run in the WebLogic Server cluster environment.

Configuration for a clustered WebLogic Server system integrated with JAM is defined by the WebLogic Server configuration, so no special clustering configuration is required for JAM. For more detailed information about WebLogic clustering and how to configure WebLogic Servers and clusters, refer to the BEA WebLogic Server Documentation Center at http://www.oracle.com/technology/documentation/index.html. Figure 2 shows JAM connecting a cluster of servers running on WebLogic Server.

Note: You must install and configure a JAM gateway on each computer in a cluster and a unique CRM for each JAM gateway. This is required no matter which configuration type you choose.

Figure 2 JAM Connecting Clustered WebLogic Servers and Mainframe

Accessing Your Legacy System Through WebLogic Server

The eGen utility installed with the BEA WebLogic Java Adapter for Mainframe generates Java applications from a COBOL copybook and other mainframe (legacy system) application information. After you generate your own Java applications, you can customize them to meet your own particular needs. For more information on the eGen utility, see the "eGen COBOL Code Generator"section in this guide. For information on using the eGen utility and examples of how it can be used to develop applications that perform discrete business operations, see the BEA WebLogic Java Adapter for Mainframe Programmers Guide and BEA WebLogic Java Adapter for Mainframe Scenarios Guide.

Figure 3 illustrates the BEA WebLogic Java Adapter for Mainframe working in the WebLogic Server and mainframe environments. The Java client applications that you have customized to meet your own particular needs make mainframe requests through the JAM gateway and the CRM to the mainframe. The mainframe responds back through the CRM and the JAM gateway. Likewise, the mainframe makes requests through the CRM and the JAM gateway to the server EJB that you have customized to meet your own particular needs. The server EJB responds back through the JAM gateway and the CRM to the mainframe.

Figure 3 JAM Connecting Java Applications with Mainframe

Providing Workflow Processing Using WebLogic Process Integrator and WebLogic XML/Non-XML Translator

The JAM plug-in allows you to use your mainframe applications in WebLogic Process Integrator workflows and initiate WebLogic Process Integrator workflows from CICS or IMS application requests. Before you can use the plug-in, you must install and configure WebLogic Process Integrator and the WebLogic XML/Non-XML Translator. For instructions on using JAM with WebLogic Process Integrator and WebLogic XML/Non-XML Translator, see the BEA Java Adapter for Mainframe Workflow Processing Guide.

Note: WebLogic Process Integrator and WebLogic XML/Non-XML Translator are available only as part of WebLogic Integration.

Getting Started with the BEA WebLogic Java Adapter for Mainframe

Table 1 presents an action list of the tasks and processes you must perform to install, configure, and use JAM. Refer to the documents listed in the action list for more detailed instructions in implementing JAM. The steps in the action list are numbered in suggested reading order.

Table 1 Getting Started with JAM Action List

| Your action... | Refer to...
--- | --- | ---
1 | Verify that system requirements have been met. | BEA WebLogic Java Adapter for Mainframe Introduction and Release Notes
2 | Determine which configuration your system requires and install the JAM product as appropriate for your configuration. | BEA WebLogic Java Adapter for Mainframe Installation Guide
3 | Configure your system to meet your requirements. | BEA WebLogic Java Adapter for Mainframe Configuration and Administration Guide
4 | Start the CRM and verify its proper operation using the CRM Monitor. | BEA WebLogic Java Adapter for Mainframe Configuration and Administration Guide
5 | Either a) Create JAM applications that initiate or accept mainframe requests through JAM. b) Configure WebLogic Process Integrator to initiate mainframe requests through JAM. | For Option a, BEA WebLogic Java Adapter for Mainframe Programming Guide and BEA WebLogic Java Adapter for Mainframe Scenarios Guide. For Option b, BEA WebLogic Java Adapter for Mainframe Workflow Processing Guide.
6 | Administer your JAM system. | BEA WebLogic Java Adapter for Mainframe Configuration and Administration Guide

Figure 4 presents a graphical overview of the tasks and processes you must perform to install, configure, and use JAM.

Figure 4 JAM Process Overview

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