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A new kind of BPM with Activiti

Tom Baeyens & Joram BarrezAlfresco

twitter: @tombaeyens @jbarrez

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Tom Baeyens

• Founder of Activiti & jBPM• Passionate about Java and BPM• http://processdevelopments.blogspot.com/

Joram Barrez

• Ex-core developer JBoss jBPM• Core developer Activiti• http://www.jorambarrez.be/

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BPM for developers

• Process = Activities + Transitions• Activity = Execution step in your application• Configure out of the box activity types

• User task• Email• Script• Web service• JMS• EJB

• Delegate to Java& scripting where necessary

• Timers

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Activiti Engine

• Essence: State machine• Persist state of an execution flow

Execution

Empl John Doe

Date 5/10/2010Doc vacation.xlsState Approved

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Transactional Control Flow

• Start process instance• Create new execution• Pass initial data in (optional)• Take transition to “Fetch data from DB”• Execute “Fetch data from DB”• Take transition to “Wait 1”• Stop interpreting process• Persist state• Return Execution

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Transactional Control Flow

INSERT INTO ACT_RU_EXECUTION (…, ACTIVITY_ID_, …) values (…, ‘Wait’, …)

Execution

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Transactional Control Flow

• Signal• Load existing execution• Pass data in (optional)• Take transition to “Wait 2”• Stop interpreting process• Update runtime execution• Return

Execution

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Transactional Control Flow

UPDATE ACT_RU_EXECUTION SET ACTIVITY_ID = ‘Wait 2’

Execution

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Transactional Control Flow

• Signal• Load existing execution• Pass data in (optional)• Take transition to “Send email”• Execute “Send email”• Take transition to “end”• Stop interpreting process• Delete runtime execution• Return Execution

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Transactional Control Flow

Execution

DELETE FROM ACT_RU_EXECUTION WHERE ID_ = ?

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Extra convenience in activity types

• Examples• Task lists • JMS message send & receive• Web service send & receive• And… everything you can do in Java

• Activity pluggability

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Extra convenience in history

• Optional, default turned on• Log every process instance

and activity instance• Activities at business levelStatistics are valuable

business intelligenceFor FREE

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Coming up

• How to implement a process with Activiti• Showing you the nitty-gritty details

• Making you an Activiti-ninja-developer-hero

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Demo

• Use case: banks shouldn’t lend money to just anybody• Thorough analysis is needed• All steps needs to be recorded in official documents• Decisions are done based on Excel decision tables

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The mortgage process

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The mortgage process

= CMIS call

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Deployment

• Collection of resources

Deployment deployment = repositoryService .createDeployment() .addClasspathResource(“mortgage-process.bpmn20.xml”) .addInputStream(“mortgage.png”) .addZipInputStream(“mortgage-docs.zip”) …

Deployment

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Deployment

• “Deploying”

repositoryService .createDeployment() .addXXX() … .deploy()

Activiti engine

bpmn

bytes

deployersProcessDefinition

Deployment

Mortgage process

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Process versioning

• Markets, customers, products, … change• Business processes change

• Activiti supports versioned process definitions

Process def “mortgage”, version = 1

Process def “mortgage”, version = 2

ProcessInstance processInstanceA = runtimeService.startProcessInstanceByKey(“mortgage”);

repositoryService.createDeployment() .addClasspathResource(“mortgage-process.bpmn20.xml”) .deploy();

ProcessInstance processInstanceB = runtimeService.startProcessInstanceByKey(“mortgage”);

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Process versioning

• But what about existing process instances?• They execute according the original process definition• “Phase-out” strategy

• New process instances• Default: latest deployed process definition• Instance migration

runtimeService.startProcessInstanceByKey(“process-key”);

ProcessDefinition procDef = repositoryService.createProcessDefinitionQuery() .name(“myProcess”) .version(2) .singleResult();runtimeService.startProcessInstanceById(procDef.getId());

Latest deployed

Specific version

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Starting the process

• ProgrammaticallyBPMN start event

ProcessInstance processInstanceA = runtimeService.startProcessInstanceByKey(“myProces”);

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Start form

• Processes often need data to run• Start event can have a start form to capture this data

• Activiti Explorer

FormInstance form = repositoryService.getStartFormInstance(“mortgage”);

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Start form

• Activiti Explorer• Supports easy-to-build-and-understand HTML forms

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User task

• Wait state• Creates a Task entry in the DB

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Service task

• Call custom business logic• Support for

• Delegation to class• Expressions (see later)

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Service task

• Soon• Webservice support

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Exclusive gateway

• Control flow• Selects 1 (and only 1) outgoing seq-flow

based on the expressions

Mail task

• Automatic step• Specific service task shipped with Activiti

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Unit testing your business processes

• With Activiti, your business processes are an integral part of your software project

• So they should be tested just the same as your regular application code …

• With unit tests !

• Activiti supports both JUnit 3 and JUnit4 style of testing your business processes

• And ships with a lot of convience for testing

• Demo

29Pic from http://silverbackapp.com

The cool stuff

• That didn’t make it into the demo• But is just too cool not to share with you

• Timers• Script support• Query API• Spring integration• Method expressions• JPA

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Timers

• Work is often time constrained• A timer boundary event can be attached

to the boundary of any task or subprocess

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Timers

• When timer fires• Current execution(s) inside scope of event are

destroyed and process continues following seq-flow going out the timer event

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Script task

• Execute a script embedded in the process definition• Any JSR-223 compliant script language• Opens up powerful capabilities

• Javascript, XPath, CMIS-script (?)

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<scriptTask id="theScriptTask" name="Execute script" scriptFormat="groovy">  <script>    sum = 0    for (i in inputArray) {      sum += i    } execution.setVariable(“myVar”, sum)  </script></scriptTask>

Query API

• No need to learn the intern data model • Powerful and uniform query API

• Deployments and process definitions

• Process instances and executions

• History

• Variables

• Tasks, jobs, users, groups, historic activities/process instances/variables, …

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repositoryService.createProcessDefinitionQuery.keyLike(“%mortgage%”).latest();

runtimeService.createProcessInstanceQuery .processDefinitionKey(“mortgage-process)”.orderByProcessInstanceId().desc();

historyService.createHistoricActivityQuery().processDefinitionId(procDefId) .activityType(“userTask”).orderByDuration().asc();

runtimeService.createProcessInstanceQuery() .variableValueGreaterThan(“amount”, 50000);

Spring integration

• First-class integration with Spring• Define and inject Activiti process engine and services• Leverage and integrate with Spring transaction

management• Delegate to Spring beans in the process definition• Resource deployment and duplicate filtering for

simplified development• Spring unit testing support

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Spring integration

• ProcessEngine as a Spring bean

• Delegate to Spring beans

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<bean id=“printer” …

Method expressions and JPA

• Besides the typical expressions that everyone supports, Activiti has

• method expressions• method parameters

• Variables, execution, …

• First-class JPA support• Store JPA entity as process variable

• Seamless integration of domain model with process• Only domain model reference is stored

• Fetch/update is done in original data store

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Throwing it all together

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Process variables

Spring bean

Decision based on JPA entity property

Update JPA entity

The Activiti Experience

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• Satisfy your Activiti itch

• One-stop-shop download:• http://www.activiti.org

• Demo: “The Activiti Experience”• Do you have an excuse for not

trying out Activiti later today?