Free «Web Services» Essay Sample
Web Service is abstract concept that must be implemented by an agent. The agent is the software and hardware that sends and received messages. Using one agent for particular web service means selecting one programming language, one day and next day can select a different agent with the same functions. Therefore to communicate messages in web service architecture is usually described by a WSDL document. In this document, the supported web service procedures and messages are described abstractly and then bound to a concrete network protocol and message format. Atypical WSDL document consists of the following elements: “types,” “message,” and “portType” for the abstract definitions; “binding “and “service” for the concrete specification. These elements are wrapped inside a “definitions” element. In the context of RPC and document style, it is the binding element that needs to have a closer look. A WSDL binding describes how the service is bound to a messaging protocol, HTTP GET/POST, MIME, or SOAP. Most used protocol for the SOAP message “SOAP over HTTP(S).
Web service tools and development environments are very good at maximizing the productivity of developing web services based apps. But, without agreement and standards on generic services that all applications can use, integration is ad-hoc and unique to each system, to create standardized web services that are: a) Developer independent, b) Application function independent, c) Middleware independent, d) User independent, e) Can enable off-the-shelf reusable application adapters from third parties.
SOA security element has more safety requirements. Each requirement may have any number of standards that support it. For example, both SSL/TLS and WS-Security provide privacy, integrity and authentication support for the messaging dimension, while the accountability requirement of the resource protection dimension does not have any supporting standards.