Web Services

XML and eBusiness Technology

Introduction

• Web services - the next big thing?• HTTP has become the network standard• XML defines business transactions• Business applications execute over the Web• Distributed computing in a heterogeneous

environment – how do you make this happen?• Web services, SOAP, Java, and networks

– Computing in the early 21st century

Four Paradigms of Computing

• Mainframe– The era of “big iron”

• Client – Server (C/S)– Networks and cheap desktop computing

• Internet Computing (n-tier architecture)– Web moves to a computing platform

• Web services– Web moves to a business platform

Web Services

• XML, Java, SOAP, and networks• Critical for B2Bi

– Used in “light EAI”

• Creates a “network application platform”– Sun ONE (Open Network Environment)– Facilitates “any to any” and “many to many” computing– Lets applications and process talk to each other– Creates a peer-to-peer computing environment– UDDI - directory of services for “client discovery”

Service Oriented Architecture

• Service provider– Creates services and publishes to registry

• Service broker– Holds information on how to find and “bind”

to a (web) service

• Service requester– Searches the registry, finds services, and

“invokes” them after “binding”

Service Oriented Architecture

ServiceProvider

ServiceRequestor

ServiceBroker

Bind

Find

Publis

h

Web Services Paradigm

• Web services are the building block of a Service Oriented Architecture (SOA)

• Publish application services• Find published services• Bind to the service found• Invoke the bound service

– Passing required parameters for proper execution of the selected service

Web Services - Protocols

• WSDL - description

• UDDI - discovery

• SOAP - messaging

• BPEL – execution

• ebXML - orchestration

• HTTP – transport

• XML – the lingua franca for data

Web Services Protocol Stack

WS - Process Architecture• Services directory

– WSDL and UDDI

• Business transaction– SOAP request / response

• SOAP envelope– Message and protocol

• Transaction details– ebXML, BPEL

• Network layer– HTTP, HTTPr, HTTPs, SMTP

WS - Process Architecture

Web Services Architecture Overview• Service creation and assembly

– A visual design environment, possibly UML

• Service delivery and service integration– Messaging interfaces to Internet and network APIs

• Applications and Web services– Web services containers– Other legacy applications

• Application platform– Identity and Policy– Security and Workflow– Collaboration services

Web Services – Architecture

Standards Services Architecture

• Standards Services Architecture:• Leverages key XML technologies

– XSLT, SOAP, WSDL

• Smart process– ebXML, BPML– UDDI

• Smart Policy– LDAP

• Smart management– SNMP and XML routing technologies

Web Services – Standards Architecture

Network Layer

• Lowest level in the Web services architecture is the conduit for transmission of XML messages

• HTTP is most common protocol in use• HTTPR (R stands for reliable)• HTTP carries traffic through firewalls

– So it is the best “business conduit”

• HTTPR provides “VAN like” services (re: EDI)– “exactly once” delivery of messages, notification, etc.

Network Layer – Logical Stack

• WSIL, WSFL, WSHT– Application services and service flow

• UDDI – Service discovery• UDDI – Service publication• WSDL – Service description• WSIL / SOAP – XML messaging• HTTP, HTTPR, SMTP, MQ, IIOP

– Network layer for messaging

Web Services Stack from WebServices.org

 

Layer Example

Service Negotiation Trading Partner Agreement

Workflow, Discovery, Registries

UDDI, ebXML registries, IBM WSFL, MS XLANG, BPEL4WS

Service Description Language WSDL/WSCL

Messaging SOAP/XML Protocol

Transport Protocols HTTP, HTTPS, FTP, SMTP

Business Issues Management, Quality of Service, Security, Open Standards

SOAP

• Simple Object Access Protocol (SOAP)

• Internet protocol for requesting a service

• Lets loosely coupled entities cooperate

• Relies on HTTP/HTTPS for transport

• Picks up where IIOP and CORBA left off– Conduit for Remote Method Invocation (RMI)

SOAP Message – 3 Parts

• The message, envelope, and “channel”

• SOAP envelope– The SOAP packet structure

• XML body of the message– The XML grammar of SOAP request

• Specification of transport binding– The “SOAP” messaging protocol

Anatomy of a SOAP Transaction

• Client SOAP– Request packet (marshal and unmarshal)

• Transport– SOAP running over HTTP (HTTPr / HTTPs)

• Supplier SOAP– Response packet (marshal and unmarshal)

SOAP Transaction

SOAP Request Code

POST /path/foo.pl HTTP/1.1Content-Type: text/xmlSOAPActor: interfaceURI#AddContent-Length: nnnn

<soap:Envelope> <soap:Body> <Add>

<arg1>24</arg1> <arg2>53.2</arg2> </Add> </soap:Body></soap:Envelope>

SOAP Response Code

200 OKContent-Type: text/xmlContent-Length: nnnn

<soap:Envelope> <soap:Body> <Response> <sum>77.2</sum>

</Response> </soap:Body></soap:Envelope>

UDDI

• Universal Description, Discovery, and Integration (UDDI) http://www.uddi.org/

• SOAP creates a request for a service– But how do you know that the service exists?– UDDI is a distributed registry (like DNS system)– Service providers post in the UDDI registry

• UDDI defines a set of SOAP messages that provide the client API for accessing a UDDI registry

UDDI Registry Record

UDDI.org

UDDI ServicesPublisher API• save_business• save_service• save_binding• save_tModel• delete_business• delete_service• delete_binding• delete_tModel• get_authToken• discard_authToken

Inquiry API• find_business• find_service• find_binding• find_tModel• get_businessDetail• get_serviceDetail• get_bindingDetail• get_tModelDetail

WSDL

• Web Service Description Language (WSDL)

• WSDL is XML based language that describes the attributes of a Web service– Register the service in the UDDI directory– Interface is the format of the SOAP request

• Request / response to execute and receive results of Web service on SOAP envelope

WSDL Document Structure

WSDL Grammar

• Message

• Operation

• portType

• Binding

• Port

• Service

WSFL

• Web Services Flow Language (WSFL)• XML based language for defining the

composition of web services• A flow composition defines how a

sequenced execution of web services perform a higher level business process

• Defines the interaction between a set of business partners executing Web services

Preparing a Web Service

• Develop the functionality you want in a service• Create the WSDL to describe the service• Generate server-side SOAP deployment• Publish deployment descriptor in UDDI registry• IBM WebSphere Studio Application Developer:

– WSDL for entry in UDDI registry– XML-Java mapping for complex Java objects– Deployment descriptor for installing (WS) on a server

IBM Web Services Zone

Using A Web Service

• Create a Java client to find and call the service• Search the UDDI registry for the desired service• From WSDL description create SOAP message• SOAP message will contain input parameters• Send SOAP request message and wait for reply• Receive SOAP response with service execution• Extract the results of service from the message

and process them through a (Java etc.) client

Web Services Process

Java

• Java is ideal development environment

• Object oriented with APIs for XML:

• Java API for XML Messaging (JAXM)

• Java API for XML Processing (JAXP)

• Java API for XML Registries (JAXR)

• Java API for XML - based RPC (JAX-RPC)

Security

• There are several key areas to security:– Identification– Authentication– Authorization– Integrity– Privacy– Auditing– Non-repudiation

B2Bi, Web services, and ebXML

• What is B2Bi?• Web services for B2Bi• What is ebXML?• ebXML initiative• ebXML architecture

– ebXML implementation– ebXML partner discovery– ebXML transaction messaging

The Challenge of B2Bi

• 100,000 companies

• Middleware doesn’t do it

• 99,999 factorial connections

• eMarketplaces didn’t fulfill it

• Integrating network business process

What is B2B Integration (B2Bi)?

Web Services for B2Bi

ebXML Initiative

• ebXML – XML, UDDI, and B2Bi

• Integrate discovery, binding, and flow

• UDDI – for discovery and binding

• ebXML - the eBusiness lexicon of B2Bi

• Creates a “pattern” for Web service flow

ebXML Architecture

ebXML Implementation

ebXML Partner Discovery

ebXML Transaction Message

Advantages to Web Services

• Flexibility for loose-coupling / late-binding

• Flexibility in scope: Internet / intranet– Limit to enterprise or extend to trading partner

• Based on HTTP, XML, and SOAP standards

• Self-describing in WSDL / UDDI registries

• Aggregate Web services for complex and threaded business process / B2Bi etc.

Microsoft.Net

Microsoft .Net Initiative

• Microsoft .Net initiative based on SOAP

• Uses Java tools / visual process design

• Designed for compatible clients on ends

• Similar use of XML and SOAP message

• More similar to COM objects than EJB

Sun ONE

• Open Network Environment

• Web services stack

• Blend servers and services

• “Smart Web Services”

• Networked business process

Smart Web Services Architecture• Smart delivery

– Aggregation, presentation and delivery– Personalization, content, and contextual sensitivity

• Smart process– Automated workflow management

• Smart policy– Identity, content and roles

• Smart management– Privacy and Security– Rights and Administration– User management

Smart Web Services Architecture

Smart Processing Overview

• Smart management– Service registration, service management– Listing in UDDI repositories, updating records

• Smart delivery– Protocol awareness and messaging options– Flexible integration with network applications

• Smart processing– Management, collaboration, and services delivery– Created a distributed network application platform

Web Services – Processing Overview

Micro Service Developer Model• XML document

– HTTP– SOAP– JAXM, JAX, RPC

• Web server– JSP– Java servlets

• Application server– JDBC– JMS– J2EE– JAXM JAX / RPC

Micro Web Services Developer Model

• From a developer's perspective a micro Web service consists of:– Web service interface and one or more service components.– The Web service interface manages and manipulates XML

messages; it can also be a front end to a legacy application.• “Service components” contain the business logic that

implements the requested service.– Business components frequently interact with external resources

and services through a variety of integration services

• A Web service communicates by passing XML documents over standard Web protocols– Using HTTP to pass SOAP, XHTML, and other XML messages

Micro Service Developer Model

Web Services Portal Model

Web Service Process Modeling

Distinguishing Business Process Modeling and Management

• Enterprise business processes – ebPML: e-business Process Modeling Language

• Executable business processes– BPEL: Business Process Execution Language

• ebXML business processes– (a.k.a. collaborations) 

• Business process activities – BPMI and BPML (and ebPML)

• Workflows and management– BPMS: Business Process Management Systems

PML – Process Modeling Languages

• BPML

• IBM WSFL

• MS XLANG

• BPML / ebPML

• BPEL, BPEL4WS

• UML

BPML

• Business Process Modeling Language• A method to bind “UML” and Web services

– The Business Process Modeling Language (BPML) is a meta-language for the modeling of business processes, just as XML is a meta-language for the modeling of business data.

– BPML provides an abstracted execution model for collaborative & transactional business processes based on the concept of a transactional finite-state machine.

BPMI.org Activities

Internal View of Loan Process

BPEL – Complete Loan Process

Tangled BPM Initiatives

ebPML

• Electronic Business Process Modeling Language– http://www.ebpml.org/

• "Business is complicated. Any solution that doesn't reflect that complexity is not a real solution. ebXML is no more complicated than it has to be in order to implement real-world business collaborations. Conversely, Web services as they are currently defined seem simple precisely because they're not trying to deal with the complexities of real business relationships involving independent enterprises."– A grain of wisdom from John Bosak -

ebPML Vision

BPMS Diagram

Key Technologies for BPMS

• XML

• B2B middleware

• Enterprise Application Integration 

• Web Services

• (Legacy Systems behind Web services)– Business Process Management Systems

BPMS Architecture

UML 2.0

• Unified Modeling Language

• Looks at the entire picture of a process from the view of actors and use cases

• State, activity, and collaboration diagrams show interactions of actors

• UML diagrams can now be saved in XML formats, aiding their use with WS

Web Service Operations

BPMS Activity

Web Service Class Diagram

Summary

• “Distributed computing” on a network platform• Computing for the early 21st Century• Uses XML, SOAP, WSDL, UDDI standards• Services are self-describing for discovery• SOAP interface to messaging interface• Java clients for request / response formatting

– Web services are applications with an IP address– Think of it as “hyper-linking” network applications!

Resources• http://www.webservices.org/• http://xml.apache.org/• http://www.uddi.org/• http://www-106.ibm.com/developerworks/webserv

ices/• http://java.sun.com/webservices/• http://www.xmethods.net/• http://www.microsoft.com/net/

Self Quiz

• What are Web services?

• Why Web services?

• What is the “protocol stack” ?

• Write out the WS process flow

• What things do Web services do well?

• Where are Web services lacking?

• What are WS process initiatives about?

Vocabulary Checklist - http://whatis.com/

• Architecture• BPEL• BPMI• BPML• ebXML• Java• J2EE• HTTP• HTTPr and HTTPs• .Net

• Protocol• Protocol stack• SOA• SOAP• Sun ONE• Transport layer• UDDI• WSDL• WSFL• XML

So what is all this XML?

• Just another markup language?

• No – the “mother of all markups”

• Technically, XML + HTML = SGML

• HTML is about presentation

• XML is about representation– Write your own markup languages– DTDs and schema define the rules

A Song Description in HTML

<dt>Hot Cop</dt><dd> by Jacques Morali, Henri Belolo,

and Victor Willis</dd><ul><li>Producer: Jacques Morali<li>Publisher: PolyGram Records<li>Length: 6:20<li>Written: 1978<li>Artist: Village People</ul>

A Song Description in XML

<song> <title>Hot Cop</title> <composer>Jacques Morali</composer> <composer >Henri Belolo</composer> <composer >Victor Willis</composer> <producer>Jacques Morali</producer> <publisher>PolyGram Records</publisher> <length>6:20</length> <year>1978</year> <artist>Village People</artist></song>