CIS-764 Database Design Service-Oriented Architecture and Web-Services Binti Sepaha

Overview  Introduction  Definitions/Concepts  Steps in Building a Web-Service  Web-Service by Example  Benefits of Web-Services  Conclusion  References

Introduction History of Software Development  Modular Approach Code reuse - sub-routines and functions Maintenance became a problem  Object-Oriented Programming Reuse code but not functionality  Component-based Software Development Reuse functionality components were written in different languages Changes became tough, redistribution was tough

Service-Oriented Architecture & Web-Services  Greater Reuse  Web Interface  Loose Coupling enables business flexibility  Use the best service provided by service providers based on the consumer’s criteria  Platform-independence  Integration of several services  Application Integration became easier

Definitions/Concepts  Service A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services. Services are long running executables.  Web-Service A Web-Service is a piece of software that makes itself available over the Internet and uses a standardized XML messaging system.  Service Provider A company that provides a service by exposing it through a dynamic discovery service.

Definitions/Concepts (contd.)  Service Consumer A program that consumes or subscribes to a service provided by a service provider.  Dynamic Discovery An intermediary between providers and consumers. Universal Description, Discovery and Integration (UDDI) is a directory service where businesses can register and search for Web services.  Message Communication means between service providers and consumers.

Definitions/Concepts (contd.)  WSDL (Web-Services Description Language) WSDL provides a way for service providers to describe the basic format of web service requests over different protocols. WSDL is used to describe ‘what’ a web service can do, ‘where’ it resides, and ‘how’ to invoke it.  SOAP (Simple Object Access Protocol) SOAP is a protocol specification that defines a uniform way of passing XML-encoded data. In also defines a way to perform remote procedure calls (RPCs) using HTTP as the underlying communication protocol. SOAP essentially provides the envelope for sending the Web Services messages.

Steps in Building a Web-Service

Steps in Building a Web-Service (contd.)  Discovery through dynamic discovery (UDDI)  Description through WSDL  Packaging through SOAP (XML)  Transport through HTTP  Network through Internet or local intranet (TCP/IP)

Web-Service by Example

Benefits of Web-Services  More reuse  Better Scalability  Service Assembly  Higher Availability  Code Mobility ( location transparency)  And many more…

Conclusion Developers must switch to Service-Oriented Architecture

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