Standard-WS - 1

Dr. Minder ChenAssociate Professor of Decision Science and MIS

George Mason University Email: MCHEN@GMU.EDU

703-993-1788

Building XML Web Services for E-Business Applications

Standard-WS - 2

Blinds and ElephantsThough each was partly in the right, and all were in the wrong!

Elephant illustration (c)2002 Jason Hunt; naturalchild.org/jason

It is massive as

a wall.

It moves air like a fan.

It is sharp like a spear.

It is soft like a rope.

It is sneaky like a snake.

It stands solid like a tree.

Standard-WS - 3Elephant illustration (c)2002 Jason Hunt; naturalchild.org/jason

It is massive as

a wall.

It moves air like a fan.

It is sharp like a spear.

It is sneaky like a snake.

It stands solid like a tree.

Diversified Views on Web Services

Web services

?

It is soft like a rope.Programmable Web

XML, SOAP, WSDL, UDDI

Business

Processes

& Services

Modularized ASP,

WS Grids

EDI, XML, B2B, SCM

RPC, Corba, RMI, DCOM

Standard-WS - 4

Definition of Web Service

Loosely coupled, reusable software components that semantically encapsulate discrete functionality and are distributed and programmatically accessible over standard Internet protocols.

Web services are a stack of emerging standards that describe a service-oriented, component-based application architecture.

Web services represent a model in which discrete tasks within e-business processes are distributed widely throughout a value net.

-- The Stencil Group

Standard-WS - 5

Where Is the Web going?

Static Content

Web

Dynamic Interactive

Web

Integrated Programmable

Web

HTML Dynamic HTML (JavaScript)

CGI (using Perl, etc.) ColdFusion, ASP, Java Servlet, JSP ASP.NET XML (Document interchange)

XML Web Services (SOAP, WSDL, UDDI)

Standard-WS - 6

Evolutions of IT ApplicationsWeb sites

(Content-oriented)

Web-based Applications

C/S Applications (Transaction-oriented)

Web Services(Distributed Computing &

Component-based development [CBD] )

Electronic Commerce(B2B: EDI & XML)

Service-Oriented E-Business Applications

Enterprise SoftwareSystems

Standard-WS - 7

Distributed Computing

Remote Procedure Call (RPC) Message Queue:

• IBM QSeries(IBM)• Message Queue (Microsoft)

Common Object Request Broker Architecture (CORBA)

Distributed Common Object Model (DCOM) Java Remote Method Invocation (RMI) J2EE - Enterprise Java Bean

Standard-WS - 8

HTTP and Firewalls

Firewall

Port 80

DCOMService

Web Service

RMIService

Client

Standard-WS - 9

•XML DTD files

•XSD filesValidation

XML/XSLApplications

XML definition

languages• XML 1.0 • XML

Schemas

XSL Standards

Standard XML software Application files

XML Standards

XML Parsers• DOM

• SAX

GeneratedDocuments formatted

in: • HTML & CSS• XML• WML

XML documents

XSL files

Standard-WS - 10

SOAP

SOAP: "Simple Object Access Protocol“• XML-RPC• SOAP 1.1• SOAP 1.2 (Working Draft)

XML-based lightweight protocol for exchanging information in a decentralized, distributed, heterogeneous environment• Encapsulates the ability to make RPC Calls • Data Encoding (serializing and de-serializing)• Message Structure• Message-Processing

Standard-WS - 11

Proxyobject

XML Web

Serviceobject

SOAPmessa

ge

XML

SOAPmessa

ge

XML

SOAPmessa

ge

XML

SOAPmessa

ge

XML

SOAP Envelope HTTP Header

SOAPrequest

XML Data

Attachments

SOAPresponse

Phase 2Deserialize

Phase 3Serialize

Phase 1Serialize

Phase 4Deserialize

Web Server

Client

XML Web Service Lifetime

Standard-WS - 12

SOAP: Encoding Complex Data

<soap:Envelope ...> <soap:Body> <GetStockResult xmlns="http://tempuri.org/"> <result> <Name>Web Service Inc.</Name> <Price>66</Price> <Ticker>WSI</Ticker> </result> </GetStockResult> </soap:Body></soap:Envelope>

Standard-WS - 13

Develop & Deploy Web Services

Add Web Ref

HTTP/WSDL

WSClass.Method(…) as

ReturnedDataType

HTTP-SOAP-IN Message

Web Services Provider

Web Services Consumer

Web ServiceSource Code

(Server)

Compiler

VS.NET

.NET ClientPlatform

Web ServiceProxy Code

ClientApplication

Web ServiceProxy Code

(client)Compiler

ClientSource Code

VS.NET

Web ServicesApplication Server

Web ServiceExecutablesDeploy

WSDL

HTTP-SOAP-OUT

Standard-WS - 14

Business &

services

info. URL to

WSDL

SOAP Response

SOAP Request

Publish

Find

Invoke

WSD

L URLs

Sear

ch crit

eria

for w

eb

serv

ices

WSDL URL

WSDL File

Service Registries

• Public UDDI• Private UDDI

WebService

Consumers

WebService

Providers

Role Operation Data flow Data/Message

Bind

n

Standard-WS - 15

Distributed Midle-Tier Components

Distributed Midle-Tier Components

Web Services

WindowsApplications

Web Applications

Mobile WebApplications

Presentation Layer Middle-Tier Layer Server Resource Layer

PDA & Pocket PC

Distributed Middle-Tier Components

.NET CFJ2ME

.NET Framework RuntimeOr Java Runtime Environment (JRE)

DataBases

Web Services

XML

Web Services

Web Services

Web Services

Web Services

Internet

Other Server

Resources

Web services in the context of a Three-Tier Application Architecture

Legacy Applications

Intranet

Standard-WS - 16

What is .NET – Industry ViewSoftware that connects people, information and devices

Standard-WS - 17

SOAP

The SOAP Envelope is a XML-based message format:

• HEAD

• BODY

Bindings for exchanging SOAP envelopes• HTTP-SOAP, HTTP-GET, HTTP-POST

• SMTP

• FTP

• Messaging queuing

Standard-WS - 18

Communication Protocol(HTTP, FTP, SMTP, etc.)

Service Description(WSDL)

Service Directory(UDDI)

Service Composition(BPEL4WS)

Sec

uri

ty(S

AM

L,

WS

-Sec

uri

ty)

Web Services Standard Stack Reference Model

(SOAP)

SOAP ExtensionReliability, Transaction

(WS-ReliableMessaging, WS-Transaction)

Messaging Protocol

Sta

nd

ard

Def

init

ion

Lan

gu

ages

(XM

L 1

.0 S

pec

ific

atio

n a

nd

XM

L S

chem

a)

Man

agem

ent

(WS

-Man

agea

bil

ity

)

Standard-WS - 19

Trading PartnersSuppliersDistributorsBusiness Partners

E-Business Integration Imperatives

Heterogeneous PlatformsERP Application PackagesProprietary AppsLegacy Applications

Consumers

REQUIREMENTSStandards based integrationConfigurable across applicationsBusiness process orientedLoosely coupledSupports an incremental approachScaleable, available, secure, manageable

B2BIntegration

EAI

B2CInternet /

Virtual Private Network

Standard-WS - 20

ITUsers

ITVendors

StandardOrganizations

Development toolsInfrastructure systems

Open standards

Propriety standards

ApplicationsIT Infrastructures

Participate via giving feedbacks on practical usefulness

Participate via contributing some IPs

Influence standards adoption

adopt support

use

develop

develop develop

compete/ cooperate

compete / cooperate

Standard-WS - 21

Web Services Adoption &

ImplementationDecisions

Technical Factors• Application

architecture• Infrastructure tools• Development tools

Standards and Stakeholders • IT Product Vendors• Systems Integrators• Enterprise Customer• WS Providers• Standard Organizations• Web services

standards

Perceived Benefits• Technical benefits• Business benefits• Operational benefits• Strategic benefits

Decision Outcomes• Targeted

applications • Technical

architecture • Development

strategies• Deployment

strategies

Driving Forces of Web services adoptions and decision

Driving Forces

Standard-WS - 22

Standard Setting

Organizations

IT Products Vendors

Systems Integration

Firmsor

Internal IT Units

EnterpriseIT

Users

IT User Community

Web services

standards

Web services development

tools and infrastructure

products

Needs for better & faster development & deployment environments

Requirements for

applications integration

Advanced integration skills and solutions

Competing standards proposals

Integrated applications

Standard-WS - 23

The relatively rapid Web services adoption rate may be contributed by the following factors:

• IT vendors are strongly endorsing of Web services standards.

• The cost of adopting Web services is marginal.

• Web services has a relatively smooth learning curve comparing to other distributed computing technology.

Standard-WS - 24

Technical benefits Business benefitsLink to

Justification for Web service adoption: Technical and business benefits

Easier integration with external systems

Faster integration

projects

Faster time to market

Competitive advantage

Software reuse

Integration with legacy systems Leverage existing

software assests

Reduce software development costs

Better integration with trading

partners

Software as Web services

New revenuestreams

Dynamic Web services composition Dynamic

e-business processes