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Table of Contents

1. Introduction
2. Existing Architecture overview of JSP web-enabled IQ Application.
3. Web-enabling using NetWeaver-Webdynpro

1. Introduction

We have considered an existing mainframe application that has already been web enabled using J2EE Environment with MVC architecture, to be replaced by SAP NetWeaver Webdynpro application with struts framework.

The scope of this document is
1. To provide overview of the sample application considered for web-enabling.
2. To provide the alternative to web enable the mainframe application keeping the existing client architecture intact and propose using NetWeaver-Webdynpro to web enable the application as an alternative to JSP

2. Existing Architecture overview of JSP web-enabled IQ Application.

The IQ application considered is a browser-based quotes system having its own DB2 database to store agent, quotes and batch information. The architecture diagram of the IQ application is as shown below.

image

Figure 1

The IQ application architecture includes the Internet Information Web Server, IQ EJB, Quantum EJB, Quantum Text EJB, SVC Components/EJB wrapper, MQ Server and the Mainframe.

Each of the EJBs namely the IQ EJB, Quantum EJB & Quantum Text EJB accesses/connect to their local databases namely DB2 to invoke the stored procedures that retrieves the non Agent/Client/Policy information i.e. quotes and related information apart from the Agent/Client/Policy data from the mainframe that needs to be displayed of the Web enabled portal screen.

IQ EJB communicates with the SVC Components/EJB wrapper to retrieve the Agent/Client/Policy data from the mainframe. The SVC Components/EJB wrapper is configured to access the MQ Server to invoke the PL1 components on the Mainframe via the MQ Server’s mainframe adapter

The IQ EJB invokes the relevant EJB in the SVC Component/Wrapper remotely using the RMI lookup. Similarly IQ EJB invokes the Quantum EJB and the Quantum Text EJB using the RMI lookup.

3. Web-enabling using NetWeaver-Webdynpro

We could web-enable the above application using Webdynpro a web enabling development tool in the NetWeaver development studio environment. This can be done keeping the entire existing mainframe application architecture intact except for the web-enabling part. This is shown in the diagram below

image

Figure 2

Instead of the web-enabling layout that was developed using JSP, the web-enabling here can be done using Webdynpro. Here the layout design and the front end logic would be developed using Webdynpro. The existing sample application uses Session Facade architecture where the Web-tier connects to middle-tier (EJB component layer) through IQ EJB which contains the required business logic.
So to access the existing application in the Webdynpro environment, it requires only accessing the IQ EJB. Since IQ EJB runs remotely in different Application Server, accessing it remotely here requires Webdynpro application to use web services. To obtain this the web service of IQ EJB component shall be created and deployed on the UDDI Server or the web service file (WSDL file).

The Use of IQ Web service is enabled by an appropriate model (auxiliary and communication classes) generated by the Web Dynpro tools. At runtime, the screen data entered by the user of the application is passed to the model through the data binding between the input fields and the context elements, and through the model binding of these context elements. The model communicates with the Web service through a client stub (a Java object that acts as a proxy for the Web service.

This is depicted in the diagram below image

Figure 3

A detailed explanation illustrating the steps for creation of a web service model is stated below:
1. The WSDL description of the IQ Web service would be created and made available from the EJB server
2. The URL address through which the corresponding WSDL description can be accessed is known.
3. In the step for creating the model in the Webdynpro tool the Create Model wizard would be used wherein the import Web Service Model option is selected.
4. A suitable model name and the corresponding package name would be entered.
5. The Select WSDL Source Option followed by the radio button UDDI or URL selection is to be done, followed by the Next button click

The screen that would appear would be as follows

image

Figure 4

6. In the next step the WSDL field would be populated with the URL address through which the corresponding WSDL description can be accessed. This could be in http: or https: format
7. This import would completed by clicking on the finish button
8. The corresponding Java proxies would then be generated as client stubs, and the model classes would be generated for the subsequent binding of context elements.
9. Once the above steps have been completed and the relevant proxy settings been done the IQWebServiceModel class and its relations would be generated
10. The next step would involve creation of binding between the component controller
11. This would be followed by mapping the view context elements to component context elements
12. Addition of the implementation of the web service would require some custom java code to be added in the custom view and view controller.

For the user to access the Webdynpro application, there exists a JSP page, which would be the default page that user would access to browse the application. The JSP page would hence direct the user to the Webdynpro view page and enable the user to browse the application.

All the communication between the IQ Application and the mainframe would be done by the SVC Components/EJB wrapper which communicates with the mainframe using the MQ-Server’s mainframe adapter.

The data exchanged between the browser and WAS and WAS and the IQ EJB would be in HTTP or HTTPS (HTTP with SSL) format. The data exchanged between the SVC components/EJB wrapper and the mainframe would be in XML format.

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