BPEL Development with ActiveBPEL

Brendan Tansey

What is BPEL?

• Business Process Execution Language for Web Services (BPEL4WS)

• Web service orchestration language

• Simple arithmetic and logical operators

• Lecture on Oct 26th!

BPEL Development

• Requires:– BPEL Engine– BPEL Developer (or text

editor, for the masochistic)

• BPEL Engine– Executes BPEL processes– IBM BPWS4J– ActiveBPEL Engine– Installation notes on Wiki

BPEL Developer

• Oracle BPEL Designer– Oracle BPEL Process

Manager (OC4J, JBOSS, BEA WebLogic)

• Eclipse BPEL Project• Parasoft BPEL Maestro• Intalio Designer• Many others

ActiveBPEL Designer

• Construct graphical workflows

• Assist with WSDL creation• Simulate workflow execution• Prepare service for

deployment• Deploy service to ActiveBPEL

server• Eclipse-based• Makes your life easier

ActiveBPEL Designer Cons• Windows-only

– Windows lab in CSC 1-67– Go to CSC 1-43 to get an

account– Install onto network drive– Make workspace on network

drive

• Quirky– Hence, presentation

ActiveBPEL Designer Demo• Create a simple web service

that adds 4 input numbers• Uses an existing web service

– Takes 4 numbers as input {a,b,c,d}

– Returns two sums as output {a+b, c+d}

• Create client for service

Live Demo! (with slides)

Using an external web service to add four numbers

Create project/BPEL

Add external web references

Create sequence

• Drag ‘Sequence’ from palette

• In sequence, insert “Operation Wizard”

• Follow wizard instructions, creating a new WSDL file in your current project

• Refresh project so new WSDL is visible

Create service instance

• Force first element of sequence to create a new instance

Using external services

• Add WSDLs as imports

Using external services• Create input and output

variables for services

Create assignment activity• Assign our service’s input

to input for other service

Invoke web service

• Create invoke activity with Operation Wizard

• Select local copy of remote WSDL (can’t use remote copy – buggy)

• Choose port type and operation

• Create new PLT• Add to existing WSDL

(buggy)

Assign service output

• Use built-in arithmetic operator

Simulating execution

Providing sample input

Error!

• Need to initialize complex types before using• Initialize with literals.<in0 xmlns="" xmlns:def="http://siffleur.cs.ualberta.ca:9999/axis/services/AddFunction1Service" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="def:Complex"> <i xmlns:tns="Sum4WSDL" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:double">0.0</i> <r xmlns:tns="Sum4WSDL" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="xsd:double">0.0</r></in0>

• Red = Invoked service’s namespace• Green = Your service’s namespace• Yellow = Variable type & element types• Magenta = Variable structure

Creating complex responses

<?xml version="1.0" encoding="UTF-8"?><ns1:addComplexReturn xmlns:ns1="urn:BeanService">

<i>4.2</i><r>5.7</r>

</ns1:addComplexReturn>

Successful simulation

Can now examine output variable

Deploying your service

• The ActiveBPEL Engine requires that all services are packaged into .bpr files.– These packages need deployment

descriptors and manifests

• These files need to be placed in the Tomcat/bpr directory

• Or, deployed through ActiveBPEL Designer (easiest)

Creating a Deployment Descriptor

Finish deployment

Change Deployment URL to Match ActiveBPEL Engine installation

‘Binding’ must be set to ‘RPC Encoded’

Creating a client

• See sample code on Wiki• String endpoint = URL of

service• URL can be found in Axis

servlet• call.setOperationName(new

QName(“”,”<processName>”);

• <processName> from BPEL Admin Console

Engine admin client

• http://siffleur.cs.ualberta.ca:9999/active-bpel/

• Can conflict with other Tomcat applications. Errors in the admin client are likely caused by this.

• Can view process graph for deployed services online

Tips

• If working from home, authenticate to access.cs.ualberta.ca to access non-standard remote ports.

• When creating an ‘invoke’ activity, copy remote WSDL to local project in order to use it. Local copy also needs to be added to web references.

More tips

• ‘Invoke’ creation wizard is buggy. If you can’t select your WSDL, click ‘Create new …’ then back to ‘Use existing …’.

• Remember the ‘…’ when creating static endpoints.

• There is more than one way to accomplish most things in ActiveBPEL.

Yet more tips

• If an import isn’t being read correctly, remove it and re-add it.

• If properties give errors when they should work, check imports, then re-select each value

References

• ActiveBPEL documentation: http://www.activebpel.org/docs/index.html

• BPEL v1.1 Specifications: http://www-128.ibm.com/developerworks/library/specification/ws-bpel/

• More on BPEL: next Tuesday in class