JBPM6 provides the flexibility to extend the default process constructs with domain-specific extensions.

The domain-specific work items (also called service nodes) specify the work that should be executed in the context of a process in a declarative approach.

Here is a simple example that shows the usage of  a custom workitem that has a few parameters.
This custom extension feature provides the ability to create a service task, a generic way to interact with external services (e.g., REST, JMS, Web service etc).

Start with the setup as shown in https://community.jboss.org/people/bpmn2user/blog/2013/12/17/jbpm6--eclipse-plugin-installation.

This example has a bpmn file that has the custom WorkItem(sample.bpmn), two WorkItem configurations files (CustomWorkItem.wid and drools.rulebase.conf), WorkItem implementation class (HelloProcessExtension.java) and test class (ProcessTest.java).

Here is the configuration file CustomWorkItem.wid that provides information about the display name, parameter types etc and it should be placed in the project classpath (in PROJECT/src/main/resources/META-INF/CustomWorkItem.wid). Any custom icons for the workitems are places in  PROJECT/src/main/resources/icons.

The definition of the workitem (CustomWorkItem.wid) needs to be registered in a project. It can be done by including the definition using the drools.WorkDefinitions property in a file drools.rulebase.conf in META-INF dircectory.

After creating a definition and registering the workitem, it will show up in designer. The Eclipse might need to be restarted after creating the configuration files(i.e, CustomWorkItem.wid and drools.rulebase.conf files in META-INF directory of the project)

The new workitem 'HelloProcessExtension' can be seen in 'Service Tasks' as shown below.

'HelloProcesExtension' node can be created inside the process using drag and drop.

A WorkItemHandler implementation class needs to be created for the 'HelloProcessExtension' node.

The WorkItemHandler should be registered at the WorkItemManager, using API as shown below (in ProcessTest.java)

After running the test class 'ProcessTest.java', following results can be seen.

Here is an example that shows task persistence using H2 database. A simple process that has a couple of human tasks as shown below is considered for this example.

This example uses the jBPM plugin for Eclipse (jBPM6 - Eclipse BPMN Modeler Installation).

This examples has a bpmn file (SampleHumanTasks.bpmn), a process test program that starts the process(TaskPersistnecTest.java or TaskPersistenceExample.java), a persistence configuration files (persistence.xml ) and a Bitronix JNDI file ( jndi.properties) .

The persistence configuration file needs to be included in META-INF folder as shown below. Please refer to JPA/Hibernate documents to know more about persistence configuration details.

This example uses H2 database to show the persistence of process state into various tables.

JBPM6 database persistence involves following categories:

1.) Process persistence: This involves persisting runtime state that represents current execution state in a specific context. The runtime state contains the minimal runtime state that is required to continue execution at a later time. This allows restoring the state of execution of all the running processes (e.g., ProcessInstanceInfo)  in the event of a failure.

2.) Human task persistence: Task management component, which is treated as a separate component, can persist all the task information (e.g, user, assignment etc) into database.

3.) History or Auditlog persistence: All the audit log information(e.g., ProcessInstanceLog, NodeInstanceLog etc)can stored in database for reporting purposes.

The database tables can be viewed in Eclipse using one of database plugins such as SQLExplorer, QuantumDB etc.

The database mapping of various tables can be seen in the JPA persistence xml file included in META-INF.

jBPM6 introduces a new module called RuntimeManager which simplies the access to KnowledgeSession (KieSession) and taskservice etc.

There are various pre-defined startegies for creating RuntimeManager, such as singleton (one session for all the requests), session per request (a new session for each request) and session per process instance (each process has its own context and all the commands get executed in that context).

This example uses singleton strategy.

Here is a code snippet that shows how to use the taskservice to start and complete a task.

After running the example successfully following results can be seen,

A SQL client can be used to examine the contents of various process, task and audit tables.

This example shows how to use a 'Rule Task' component within a jBPM6 process using the example shown in JBPM5 - RuleTask Example Using a Rule File and it is illustrated using drools/jbpm Eclipse plugin (Drools 6 - Eclipse Plugin Installation and Hello World Example).

This example has a loop condition which is determined using the rules based on the location of the user and the starting condition.This example has a loop condition which is determined using the rules based on the location of the user and the starting condition.

'LoopConditionRules' is a 'Rule Task' component and it needs to have a valid RuleFlowGroup name (e.g.,  EvalLoopcondistion as shown below).

The RuleFlowGroup set in the previous step has to match with the 'ruleflow-group' name in the 'drl' rules file as shown below.

Here is the sample test code to start the process after setting the initial parameters.

This example has a bpmn file (processRuleslooptest777.bpmn), model file (HelloProcessModel.java), rules file (LoopConditionRules.drl) and a test file (ProcessRuleTest.java). After running ProcessRuleTest successfully, following results can be seen.

Here are the manual steps to install jBPM6 Modeler and run a sample example in Eclipse.

1.) Download Eclipse Juno:

http://download.eclipse.org/technology/epp/downloads/release/juno/SR2/eclipse-java-juno-SR2-win32-x86_64.zip

Unzip this into a directory, say jbpm6

2.) Download Drools and jBPM6 plugin, i.e.,:

http://download.jboss.org/drools/release/6.0.0.Final/droolsjbpm-tools-distribution-6.0.0.Final.zip

Unzip this plugin to a temp directory, say TEMP\droolsjbpm-tools-distribution-6.0.0.Final. Copy 'features' and 'plugins' directories from TEMP\droolsjbpm-tools-distribution-6.0.0.Final into

JBPM6\eclipse

3.)  Install the BPMN 2 plug-in (http://projects.eclipse.org/projects/soa.bpmn2-modeler) using the update link http://download.eclipse.org/bpmn2-modeler/updates/juno/0.2.7/

It is required to have a runtime dependant libraries that a jBPM6 sample can use.

4.) Download the libraries (jbpm-6.0.0.Final-bin.zip ) from

http://sourceforge.net/projects/jbpm/files/jBPM%206/jbpm-6.0.0.Final/jbpm-6.0.0.Final-bin.zip/download

and unzip into a directory, say JBPM6\runtime.

Set 'Installed jBPM Runtimes' to the runtime directory as shown below (Window->Preferences->Installed jBPM Runtimes)

5.) Craete a sample jBPM Project using File->New->Project->jBPM->jBPM Project