Building Web Service using BPWS4J 徐天送 2004/7/14. References Suhayi Masud, “Building a Real-World Web Service” part 1~part4, XML Journal, Feb~May 2003.

Building Web Service using BPWS4J

徐天送2004/7/14

References

Suhayi Masud, “Building a Real-World Web Service” part 1~part4, XML Journal, Feb~May 2003

Outline

Web Service Overview BPEL & its Components BPEL Activities Example Conclusion

Web Service Overview Evolution of the Web

Generation 1

Static HTML

HTML

Generation 2

Web Applications

HTMLHTML, XML

HTML, XML

Generation 3

Web Services

Web Service OverviewService-Oriented Architure (SOA)

ServiceRequestor

ServiceDirectory

ServiceProvider

PUBLISH

1

FIND

2

BIND3

Web Service OverviewUnderlying Technology

Ubiquitous Communications: Internet

Universal Data Format: XML

Wire Format: Service Interactions: SOAP

Description: Formal Service Descriptions: WSDL

Directory: Publish & Find Services: UDDI

Web Service OverviewProblem

However, just use Web Service doesn’t support E Business Dialogue

Because Web Service is … Stateless Unreliable

Ubiquitous Communications: Internet

Universal Data Format: XML

Wire Format: Service Interactions: SOAP

Description: Formal Service Descriptions: WSDL

Directory: Publish & Find Services: UDDI

Process: Services Interoperation: BPEL

BPEL

Choreography languages are built on top of the WSDL, it focus on composing stateless Web Services into state-aware e-businessine dialogues.

BPEL defines the choreography of Web Services and the role of the business partners involved in the process.

And the BPWS4J implements BPEL, developed by IBM,

BPEL

BPEL Activities

Basic activities

Invoke Receive Reply

Assign EmptyWait

Throw

!

Sequence Switch While

Structured activities

Flow Pick

Scope

BPEL Activities

Structured Activities Ordinary Sequential Control

sequence, switch, while Concurrency and Synchronization

flow Nondeterministic Choice

pick

Example

Example 1: Authentication

Environment: Tomcat + BPWS4J Test Client: Use Axis SOAP API

Example 1

Web Server(Tomcat)

Id, password

OK or FailureBrowser

Service Provider(BPWS4J)

Call Web Service

Process

receive

invoke

reply

Authentication.bpel

<receive>

<invoke>

<reply>

WSDL

WSDL

Java App

LookupUserService.java

lookupUser.wsdl

Authentication.wsdl

Java App

Client

SOAP

Partner

Variables

Process

Deploy

Deploy OK

Client

Conclusion

Web Service is Stateless, Unreliable, so the BPEL support Process into Web Service.