2006 IEEE International Conference on Web Services ICWS 2006

Overview

Contents

Introduction to Web Services SOA WS-* Standrads Amazon Web Services Complex Events Processing

Introduction to Web Services

Web Services: W3C Definition

A Web service is a software system Identified by a URL, whose public interfaces and

bindings are defined and described using XML

Its definition can be discovered by other software systems

These systems may then interact with the Web service using XML based messages conveyed by Internet

protocols

Web Services

Web services are an emerging technology that offer a solution for providing a common collaborative architecture

Web services provide functional building blocks which are not tied to any particular programming language or hardware platform

They are accessible over standard Internet protocols

The Evolution

Online systems replace Batch systems Graphical User Interfaces replace “green”

screens Networked systems replace standalone

systems Internet based systems replace LAN based

systems Future ???

Web Services replace simple Internet and LAN based systems

Web Services Technologies

XML (eXtensible Markup Language) markup language that underlies most of the specifications used for Web

services SOAP (Simple Object Access Protocol)

(Simple Object Access Protocol), similar to JDBC, is a network, transport, and programming language and platform neutral protocol that allows a client to call a remote service. The message format is XML.

WSDL (Web services description language) An XML-based interface and implementation description language. The

service provider uses a WSDL document in order to specify the operations a Web service provides. 

UDDI (universal description, discovery, and integration) Both a client-side API and a SOAP-based server implementation that can be

used to store and retrieve information on service providers and Web services.

How it works

A Web Service is a URL-addressable software resource that performs functions (or a function)

Web Services communicate using standard protocol known as SOAP (Simple Object Access Protocol)

A Web Service is located by its listing in a Universal Discovery, Description and Integration (UDDI) directory

Web Services Integration

In a lot of organizations, the data and logic of one application are basically useless to other applicationsWhen an application and its data are isolated

from other applications, we often say that they are in “silos”

Web Services are better at sharing data and functions The result is that the “silos” come down, and

previously isolated systems can talk to each other

Web Services Access

Web Services are especially good at providing access through different interfaces

A Web Service can have a dedicated client application, but it can also be readily accessed through browsers, wireless devices, voice-activated interfaces, and so on

Adding new access methods is much simpler than with a traditional application

Web Services Flexibility

One of the more important innovations in Web Services is “machine-to-machine communications”

This means that a Web Service can ask another Web Service to do something, and that Web Service can ask another Web Service to do something, and so on

In the future, many Web Services will really just be aggregations of other Web Services

Web Services Application Assembly

Future applications will be assembled from a diverse group of web services, aggregating functionality

Reusability is extended to the execution level, versus reusability from just the design and construction level

SOAP

Simple Object Access Protocol

SOAP is an open protocol specification defining a uniform way of performing RPCs using HTTP as the underlying communications protocol with XML for the data serialization.

How Is a Service Described?

WSDL (Web Service Description Language)XML-basedW3C for standard

How Do I Find Web Services?

UDDI project by Microsoft, IBM, and others Take a look at uddi.org Websites

//www.xmethods.net //www.salcentral.com

XMethods

Currency Exchange

Using the Currency Exchange Web Service

RV Application

CurrencyExchangeWS

Internet

Current Web Service Protocol Stack

Adoption of Web Service Protocols