© Adastra Group

&

jBPM & BPMN

jPrase

Vít Kotačka

24. 11. 2011

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Agenda

BPMN� Overview

jBPM� JBoss Middleware & BRMS� Core Engine API� Process Nodes� Human Tasks� Testing & debugging

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BPMN Overview

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Business Process Model and Notation

Graphical representation for specifying business processes. Providing a notation that is intuitive to business users :-) Maintained by OMG (Object Management Group). Similar to Activity Diagrams from UML. Provides a mapping between

the graphics of the notationand the underlying constructsof execution languages (BPEL).

Shows the flow of data (messages), but it is not a data flow diagram.

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Example Diagram Business Process BPMN

StartEvent1

Activity2

EndEvent1

(from Use Case)

Use Case1

Activity1

Activity3

Activity4

Firs

tLin

eS

ec

on

dL

ine

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Elements

Flow objects� Activity� Event� Gateway

Connecting object� Sequence flow� Message flow� Association

Swim lanes� Pool� Lane

Artifacts� Data object� Group

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Activities

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Events

Start Event Stop Event Intermediate Event

� Interrupting� Non-interrupting

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Gateways

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Swimlines

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72 Implementations

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JBoss Middleware & BRMS

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JBoss Enterprise Middleware

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JBoss Enterprise SOA

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Drools/JBoss BRMS

Drools Guvnor: A centralised repository for Drools Knowledge Bases. The repository component is where you can store versions of rules, models, functions, processes etc.

Drools Expert: A forward chaining rule engine based on Rete algorithm.

jBPM:  A light-weight, extensible workflow engine written in pure Java that allows to execute business processes using the latest BPMN 2.0 specification.

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Core Engine API

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Core Engine

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Knowledge Base

Contains a reference to all the relevant process definitions. Can be shared across sessions. Usually is only created once (at the start of the application). Can be dynamically changed (add/remove process at runtime).

KnowledgeBuilder kBuilder =KnowledgeBuilderFactory

.newKnowledgeBuilder();kBuilder.add(ResourceFactory

.newClassPathResource("hello.bpmn"),ResourceType.BPMN2);

KnowledgeBase kBase =kBuilder.newKnowledgeBase();

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Session

Can be created based on a knowledge base. Are used to execute processes and interact with engine. Multiple sessions can be created (independency, scalability). Is relatively lightweight.

StatefulKnowledgeSession session =kBase.newStatefulKnowledgeSession();

ProcessInstance process =session.startProcess(

"com.adastracorp.jbpm.hello");

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Events

Session can register listeners. ProcessEventListener  listens to process-related events. KnowledgeRuntimeLoggerFactory adds logger to session.

� console logger� file logger

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ProcessEventListener

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Process Nodes

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Process Node Types

Events: They are used to model the occurrence of a particular event.

Activities: These define the different actions that need to be performed during the execution of the process.

Gateways: Can be used to define multiple paths in the process.

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Events

Start Event: The start of the process. End Events

�End Event: The end of the process.�Throwing Error Event: Can be used to signal

an exceptional condition in the process. Intermediate Events

�Catching Timer Event: A timer that can trigger one or multiple times after a given period of time.

�Catching Signal Event: Can be used to respond to internal or external events during the execution of the process.

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Gateways

Diverging Gateway� AND (parallel)� XOR (exclusive)� OR (inclusive)

Converging Gateway� AND� XOR

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Activities

Script Task: A script that should be executed in this process. Can access any variables and globals.

Service Task: An (abstract) unit of work that should be executed in this process (work that is executed outside the process engine).

User Task:  An (atomic) task that need to be executed by human actors.

Reusable Sub-process:  An invocation of another process from within this process.

Business Rule Task: A set of rules that need to be evaluated. Rules are defined in separate files using the Drools rule format.

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Activities

Embedded Sub-process: A Sub-Process is a node that can contain other nodes so that it acts as a node container.  If you use a terminating event node inside a sub-process, you are terminating the top-level process instance, not just that sub-process.

Mulit-instance Sub-process: Allows you to execute the contained process segment multiple times, once for each element in a collection.

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Human Tasks

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Human Tasks

Based on the WS-HumanTask specification. An atomic task that needs to be executed by a human actor.  Can be assigned to

� one specific user� one or more groups

Can be used in combination with swimlanes to assign multiple human tasks to the same actor.

Human task service� manages the life cycle of the tasks (creation, claiming, completion, etc.)� stores the state of all the tasks� supports features like internationalization, calendar integration, different

types of assignments, delegation, deadlines, etc.

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Human Task Model

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Human Task Life-cycle

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Testing & debugging

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Process Instance(s) View shows the currently running process instances.

Human Task View can connect to a running human task service and request the relevant tasks for a particular user.

Audit View is a log of all events that were logged from the session.

Debugging

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What has been omitted

Rule Tasks Persistence Transactions Domain-specific processes Process (Knowledge) repository Business Activity Monitoring Flexible Processes

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Sources

http://www.bpmn.org/ http://www.bpmb.de/images/BPMN2_0_Poster_EN.pdf http://www.jboss.org/jbpm

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