Web Services
Purpose
Web services are modules in modern, service-oriented software architectures. With the help of Web services, IT infrastructures can be converted – step by step – into service-oriented architectures.
A Web service is a modularized, executable unit. It can be called in heterogeneous system landscapes and is not restricted to a single host system. Each output is determined based on the given input parameters. This output is then passed back to the caller. For example, Web services can serve to perform a credit card check, convert a currency amount, send a price query to a provider, or simply to place an order. Also, industrial manufacturers can provide their customers, partners, and suppliers with Web services for implementation in their own programs in order to set up cross-system supply chain solutions.
Implementation Notes
SAP NetWeaver implements the following basic standards for Web services: eXtensible Markup Language (XML); Simple Object Access Protocol (SOAP); Web Service Definition Language (WSDL); and Universal Description, Discovery, and Integration (UDDI).
Web services and Web service standards develop quickly; new standards are being introduced continually by standardization committees. Enhanced standards – such as security standards or additional protocols – are continuously updated and integrated into the Web Service Framework by SAP.
Integration
Companies can enhance their solutions using ABAP and Java Web Services.
The Web Service Framework consists of:
● The development environment for the ABAP Engine
● The development environment for the J2EE Engine
● Tools that support UDDI registration and
● An interoperable SOAP runtime (ABAP and J2EE Engine)
SOAP requests
are processed using the
Internet Communication
Framework.
Web Services and the SAP Exchange Infrastructure
Proxy programming
for ABAP proxies in the
SAP Exchange
Infrastructure and for Web service proxies has been simplified. The
advantage of this is that both technologies can be implemented so that they
complement one another. Messages can be sent and received either using the XI
runtime or the Web service runtime.
Additional proxy runtime services can be controlled using protocols that you request using a proxy method. The features you have available depend on whether you are using the Web Service Framework or the Exchange Infrastructure for communication.
Features
The ABAP Workbench offers an environment where you can publish, search for, and call Web services. It enables the SAP Web Application Server to act both as a server and client for Web services.
The Web service infrastructure enables developers to:
● Publish function modules that were implemented as RFC-enabled function modules, function groups, BAPIs, or XI message interfaces. These include functions that are provided in the SAP standard system or functions that have been developed by customers or partners. The Web service can be used across the entire Internet using standard protocols and can easily be added to any development environment (refer to Creating a Service Definition).
● Configure Web services and Web service clients in the SOA Manager (refer to: SOA Manager)
● Monitor Web services in the SOA Manager (refer to: Display Logging and Traces)
● Consume Web services from programs, irrespective of where they were stored or how they were implemented Business processes can be implemented across several systems, either within an enterprise or across several enterprises. (See also Consuming Web Services).
The Web service runtime supports Web Services Reliable Messaging (WSRM). WSRM ensures reliable message transmission between the consumer and the provider.
Asynchronous services of an Enhancement Package or the Enterprise Services Repository (SAP NetWeaver Composition Environment 7.1 / SAP NetWeaver 7.1) can be processed.
For more information, see Creating Enterprise Services Repository 7.1 Consumers/Providers.
● Publishing a Web service
From the ABAP back end, it is possible to publish services in a registry (see Publishing a Web Service).
More information: