6.2 Enterprise Information System Integration Scenarios

There are any number of configurations in which a J2EE application might be structured to access an enterprise information system. The following sections illustrate a few typical enterprise information system integration scenarios.

6.2.1 An Internet E-Store Application

Company A has an e-store application based on the J2EE platform. This application is composed of a set of enterprise beans, JSP pages, and servlets that collaborate to provide the overall functionality of the application. The database stores data related to product catalogs, shopping carts, customer registration and profiles, transaction status and records, and order status.

The architecture of this application is illustrated in Figure 6.1.

Figure 6.1 An Internet E-Store Application

A customer uses a Web browser to initiate an e-commerce transaction with the e-store application. A customer browses the catalog, makes a selection of products, puts the product selection into a shopping cart, enters a user name and password to initiate a secure transaction, fills in order related information, and finally places an order. In this scenario, the e-store application uses an existing database that already contains product and inventory information to store all persistent information about customers and their transactions.

6.2.2 An Intranet Human Resources Application

Company B has developed and deployed an employee self-service application based on the J2EE platform. This application supports a Web interface to existing human resources applications supported by the enterprise resource planning system from vendor X and provides additional business processes that are customized to the needs of company B.

Figure 6.2 illustrates an architecture for this application. The middle tier is composed of enterprise beans and JSP pages that provide customization of business processes and support a company standardized Web interface. This application enables an employee (under the different roles of Manager, HR manager, and Employee) to perform various personnel management functions: personal information management, payroll management, compensation management, benefits administration, travel management, and cost planning.

The IT department of company B deploys this application and enterprise resource planning system in a secure environment at a single physical location. Access to the application is permitted only to employees of the organization based on their roles and access privileges, and within the confines of the organization-wide intranet.

Figure 6.2 An Intranet Human Resources Application

6.2.3 A Distributed Purchasing Application

Company C has a distributed purchasing application. This application enables an employee to use a Web-based interface to perform multiple purchasing transactions. An employee can manage the whole procurement process, from creating a purchase requisition to getting invoice approval. This application also integrates with the existing financial applications in the enterprise for tracking financial aspects of the procurement business processes.

Figure 6.3 illustrates an architecture for this application. The application as developed and deployed on the J2EE platform, is composed of JSP pages, enterprise beans, and existing information systems. The enterprise beans integrate a logistics application that provides integrated purchasing and inventory management functions from vendor X and another that provides financial accounting functions from vendor Y.

Figure 6.3 A Distributed Purchasing Application

Company C is a large decentralized enterprise with geographically distributed business units and departments. In this scenario, system X and system Y are managed by different IT departments and have been deployed at secured data centers in different geographic locations. The integrated purchasing application is deployed at a location different from either system X or system Y.

System X and System Y are in different security domains; they use different security technologies and have their own specific security policies and mechanisms. The distributed purchasing application is deployed in a security domain that is different from either that of system X or system Y.