WebSphere SAP Adapter Programming Basics

Introduced

Since 1998, IBM has introduced Java as a tool for accessing the SAP Business Application Programming Interface (BAPI) and remote function calls (RFCs). IBM's early implementation of the server-side Java role means that the quality of service (QoS) and reliability of the runtime components will become as important as the tools themselves. This led to the visualage of Java and its highly reliable runtime built on the IBM Common Connectivity Framework (CCF).

Using the WebSphere Studio development tool Family, IBM accepted the J2C/JCA standard and combined them as the infrastructure of its new tool and a source-open platform. With the advent of this new tool, a new structure that uses the concept of Web Services Description Language (WSDL) as a method of describing services is introduced together with the concept of enterprise services. Although the previous generation of SAP tools is based on CCF, a new generation of tools provides a background mechanism for communicating with the server using a Java module that utilizes resource adapter file (RAR) files. This provides a standard, tool-independent approach to a RAR file that interacts with all backend tools to enable developers of front-end Web applications and back-end applications to understand, support, and communicate with each other without caring what tools or access scenarios are used.

IBM provides a RAR file that interacts with the WebSphere product and SAP system, called the WebSphere Adapter for mySAP.com. In this article, I'll introduce an overview of IBM's next-generation SAP tools and how to work with WebSphere Studio application developer, as well as an introduction to Enterprise services.

WebSphere Studio JCA Tool

The available features in the WebSphere Studio application Developer Consolidated version (hereafter referred to application Developer) are three key components that are important for enterprise application consolidation tasks:

• Enterprise Services

· JCA Tool Plug-in

• Business Process

In the new tool, Enterprise Services are used as a mechanism for connecting back-end data, such as connecting data on an SAP server. This connection to the back end can occur in the following situations:

• During the design period

Using the JCA tool plug-in, application developer connects to an SAP server, finds the appropriate BAPI, constructs a WSDL file to describe them, constructs the proxy bean component, and so on.

• During run time

Using the WebSphere Adapter for mySAP.com (hereinafter referred to as the WebSphere SAP adapter), once you have a WSDL file that describes them, there are two ways to access the backend:

1. Build agent bean components that do not use enterprise services.

2. The bean component that builds the agent uses Enterprise services to enable it to use automatic management connections, data flows, and so on.

Before discussing these methods in detail, let's take a closer look at these component methods, Enterprise Services, JCA tool Plug-ins, and business process processes.

Corporate Services

Consider that an enterprise service is fully described using WSDL as a class of operating procedures that exist in your enterprise application. Unlike network services, which typically use soap access to data sources on HTTP, an enterprise service can be bound to any data source on any protocol. In the case of SAP, an enterprise service will use the WebSphere SAP adapter to reach the required BAPI/RFC on the SAP server. Figure 1 shows the Enterprise Services WSDL document structure:

Figure 1WSDL Documentation