Chapter 9. Core Engine: Examples

There is a separate jBPM examples module that contains a set of example processes that show how to use the jBPM engine and the behavior or the different process constructs as defined by the BPMN 2.0 specification.

To start using these, simply unzip the file somewhere and open up your Eclipse development environment with all required plugins installed. If you don't know how to do this yet, take a look at the installer chapter, where you can learn how to create a demo environment, including a fully configured Eclipse IDE, using the jBPM installer. You can also take a look at the Eclipse plugin chapter if you want to learn how to manually install and configure this.

To take a look at the examples, simply import the downloaded examples project into Eclipse (File -> Import ... -> Under General: Existing Projects into Workspace), browse to the folder where you unzipped the jBPM examples artefact and click finish. This should import the examples project in your workspace, so you can start looking at the processes and executing the classes.

9.2. Examples

The examples module contains a number of examples, from basic to advanced:

Looping: An example that shows how you can use exclusive gateways to loop a part your process until the loop condition is no longer valid. The process takes the 'count' (the number of times the loop needs to be repeated) as input and simply prints out a statement during every loop until the process is completed.
MultiInstance: This example shows how to execute a sub-process for each element in a collection. The process takes a collection of names as input and creates a review task for a sales representative for each person in that list. The process completes if the task has been executed for every person on that list.
Evaluation: A performance evaluation process that shows how to integrate human actors in the process. While the basic example simply shows tasks assigned to predefined users, the more advanced version shows data passing from the process to the task and back, group assignment, task delegation, etc.
HumanTask: An advanced example when using human tasks. It shows how to do data passing between tasks, task forms, swimlanes, etc. This example can also be deployed to the Guvnor repository (including all the forms etc.) and executed on the jBPM console out-of-the-box.
Request: An advanced example that shows various ways in which processes and rules can work together, like a rule task for invoking validation rules, rules as expression language for constraints inside the process, rules for exception handling, event processing for monitoring, ad hoc rules for more flexible processes, etc.

9.3. Unit tests

The examples project contains a large number of simple BPMN2 processes for each of the different node types that are supported by jBPM5. In the junit folder under src/main/resources you can for example find process examples for constructs like a conditional start event, exclusive diverging gateways using default connections, etc. So if you're looking for a simple working example that shows the behavior of one specific element, you can probably find one here. The folder already contains well over 50 sample processes. Simply double-click them to open them in the graphical editor.

Each of those processes is also accompanied by a small junit test that tests the implementation of that construct. The org.jbpm.examples.junit.BPMN2JUnitTests class contains one test for each of the processes in the junit resources folder. You can execute these tests yourself by selecting the method you want to execute (or the entire class) and right-click and then Run as -> JUnit test.

Check out the chapter on testing and debugging if you want to learn more how to debug these example processes.

Chapter 9. Core Engine: Examples

9.1. jBPM Examples

9.2. Examples

9.3. Unit tests