df-bpmn
Meta Model
Open BPMN provides a Java Meta Model used to create, load and manipulate a BPMN model programmatically. The Meta Model includes factory and builder classes to easily operate on a BPMN model instance. The library is based on the org.w3c.dom XML API and operates directly on the dom Nodes which makes this Meta Model very flexible. The Open BPMN Meta Model allows you to handle any kind of BPMN model and also work with BPMN 2.0 extensions or add your own extensions.
The BPMNModelFactory
The class BPMNModelFactory provides methods to create ane model from scratch or to load an existing one. The BPMNModelFactory returns a BPMNModel instance to be used to read, update or delete elements.
Create a New Model
The following example shows how to create a empty BPMN model file:
String exporter = "demo";
String version = "1.0.0";
String targetNameSpace = "http://org.openbpmn";
BPMNModel model = BPMNModelFactory.createInstance(exporter, version, targetNameSpace);
model.save("src/test/resources/create-process_1.bpmn");
This file contains a default process with no elements. With the default process instance you can add BPMN flow elements:
BPMNModel model = BPMNModelFactory.createInstance(exporter, version, targetNameSpace);
BPMNProcess processContext = model.openDefaultProcess();
processContext.addEvent("start_1","Start",EventType.START);
processContext.addEvent("end_1","End",EventType.END);
processContext.addTask("task_1","Task",TaskType.TASK);
model.save("src/test/resources/create-process_1.bpmn");
Load an existing Model
To load a model instance call the read method. Again you can open the default process with “openDefaultProcess” or you can
open a specific process within your model by its id:
// load model
BPMNModel model = BPMNModelFactory.read("/process_1-empty-1.bpmn");
// open default process....
BPMNProcess defaultProcess = model.openProcess(null);
// add a second process
BPMNProcess secondProcess = model.buildProcess("P-000002","Example");
// store the model
model.save("src/test/resources/process_1-update-1.bpmn");
Collaboration Model
If a BPMN model contains more than one process it is called a collaboration model. Such a model defines Participants where each holds one process. You can easily extend a simple model to become a collaboration model by creating additional Participants:
BPMNModel model = BPMNModelFactory.createInstance(exporter, version, targetNameSpace);
BPMNProcess processContext = model.addParticipant("participant_1", "Sales Team");
model.save("src/test/resources/create-process_1.bpmn");
Note: Each participant contains it own process. You can open the participant process by calling ‘openProcess()’ or you can open the process by its ID. In addition the model also contains a default process which is also called the ‘Public’ process which is not contained in a Pool
Positioning Elements
Working with a graphical editor like Open BPMN allows you to move BPMN Elements within a diagram. In case of a BPMN Collaboration Model this means moving a BPMN Element from one Pool into another the process assignment of the BPMN element changes. The position of a BPMN element defines to which process the element belongs to. The Open BPMN Meta Model makes this process transparent by automatically updating the process assignment whenever you change the position of a BPMN element. This also applies to lanes within a pool.
// create a model with 2 participants
Participant participantSales = model.addParticipant("Sales Team");
participantSales.setBounds(10, 10,700, 300);
BPMNProcess salesProcess = participantSales.openProcess();
Participant participantMarketing = model.addParticipant("Marketing Team");
participantMarketing.setBounds(10, 400,700, 300);
BPMNProcess marketingProcess = participantMarketing.openProcess();
// add a new task
Activity task = defaultProcess.addTask("task_1", "Task", BPMNTypes.TASK);
task.setPosition(50, 50);
// The task is now part of the sales process
assertTrue(salesProcess == task.getBpmnProcess());
// change position....
task.setPosition(50, 450);
// The task is now be part of the marketing process
assertTrue(marketingProcess == task.getBpmnProcess());