Package my.package.info

import java.io.IOException;
import java.util.HashMap;
import java.util.List;

import org.eclipse.bpmn2.Definitions;
import org.eclipse.bpmn2.FlowElement;
import org.eclipse.bpmn2.RootElement;
import org.eclipse.bpmn2.SequenceFlow;
import org.eclipse.bpmn2.MessageFlow;
import org.eclipse.bpmn2.impl.MessageFlowImpl;
import org.eclipse.bpmn2.impl.SequenceFlowImpl;
import org.eclipse.bpmn2.util.Bpmn2ResourceFactoryImpl;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.xmi.XMLResource;


public class MyBPMN2ModelReader {
	public void ReadThisModel(String theBPMNFile) throws IOException {
		URI uri = URI.createURI(theBPMNFile);
		//URI uri = URI.createURI("SampleProcess.bpmn");
		Bpmn2ResourceFactoryImpl resFactory = new Bpmn2ResourceFactoryImpl();
		Resource resource = resFactory.createResource(uri);
		
		// We need this option because all object references in the file are "by ID"
		// instead of the document reference "URI#fragment" form.
		HashMap<Object, Object> options = new HashMap<Object, Object>();
		options.put(XMLResource.OPTION_DEFER_IDREF_RESOLUTION, true);
		
		// Load the resource
		resource.load(options);
		
		// This is the root element of the XML document
		Definitions d = getDefinitions(resource);

		// Print all elements contained in all Processes found
		List<RootElement> rootElements = d.getRootElements();
		for (RootElement re : rootElements) {
			if (re instanceof org.eclipse.bpmn2.Process) {
				org.eclipse.bpmn2.Process process = (org.eclipse.bpmn2.Process) re;
				System.out.println("Process: name="+process.getName()+" ID="+process.getId());
				for (FlowElement fe : process.getFlowElements()) {
					if (fe instanceof MessageFlowImpl) {
						MessageFlow mf = ((MessageFlow) fe);
						System.out.println("Message flow found.");
					}
					if (fe instanceof SequenceFlowImpl) {
						SequenceFlow sf = ((SequenceFlow) fe);
						if (sf != null) {
							String source = "";
							String target = "";
							if (sf.getSourceRef() != null)
								source = sf.getSourceRef().getId();
							if (sf.getTargetRef() != null)
								target = sf.getTargetRef().getId();
							System.out.println("Sequence Flow: " + source + " -> " + target);
						}
					}
					else {
						System.out.println(fe.eClass().getName()+": name="+fe.getName()+" ID="+fe.getId());
					}
				}

			}
		}
	}
	
	private static Definitions getDefinitions(Resource resource) {
		if (resource!=null && !resource.getContents().isEmpty() && !resource.getContents().get(0).eContents().isEmpty()) {
			// Search for a Definitions object in this Resource
			for (EObject e : resource.getContents()) {
				for (Object o : e.eContents()) {
					if (o instanceof Definitions)
						return (Definitions) o;
				}
			}
		}
		return null;
	}
}

import java.io.IOException;
public class MyBPMN2ModelReaderTest {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		MyBPMN2ModelReader myReader = new MyBPMN2ModelReader();
		myReader.ReadThisModel("testMessageFlow.bpmn");
	}
}

for (RootElement re : rootElements) {
			if (re instanceof Collaboration) {
				Collaboration co = (Collaboration) re;
				System.out.println("Collaboration: name = " + co.getName() +
						" ID = " + co.getId() + "\n");
				for(MessageFlow mf : co.getMessageFlows()) {
					System.out.println("Message Flow: = " + mf.getName());
					InteractionNode src = mf.getSourceRef();
					InteractionNode targ = mf.getTargetRef();
					System.out.println("Source = " + src.toString());
					System.out.println("Target = " + targ.toString());
					List<ConversationLink> srcLinks = src.getOutgoingConversationLinks(); // UnsupportedOperationException line.
					List<ConversationLink> tarLinks = targ.getIncomingConversationLinks();
	 				for(ConversationLink cl : srcLinks) {
						System.out.println("Source = " + cl.getName());
	 				}
	 				for(ConversationLink cl : tarLinks) {
						System.out.println("Target = " + cl.getName());
	 				}
				}
			}
                // .... further code for other elements.
}

for (RootElement re : rootElements) {
			if (re instanceof Collaboration) {
				Collaboration co = (Collaboration) re;
				System.out.println("Collaboration: name = " + co.getName() +
						" ID = " + co.getId() + "\n");
				//System.out.println("Completed adding collaboration to instantiated ontology.");
				for(Participant pt : co.getParticipants()) {
					System.out.println("Participant = " + pt.getId());
                                       org.eclipse.bpmn2.Process procRef = pt.getProcessRef(); // The getId() call to this ProcessRef does not return a Procee Id
		                       String pRefId = ""; //NullpointerException is because of this line.
// I have written the following code to understand how I can use eGet function that takes EStructuralFeature, but I need a way to specify the correct EStructuralFeature to access the processRef of Participant. This code results in exception.
		                       EObject eObject = (EObject) pt.getProcessRef();
		                       EList<EStructuralFeature> allFeatures = eObject.eClass().getEAllStructuralFeatures();
		                      for(EStructuralFeature esf : allFeatures)
		                          {
		                          Object o = eObject.eGet(esf);
		                          System.out.println("Class of Object o = " + o.getClass().getName());
		                         If(o instanceof String)
		                            {
		                               pRefId = (String) o; // Because o is one of the EList and not a String instance, I should not see anything but a NullPointerException as pRefId is set to null (pRefId = "";)
		                            }
		                        }
				}
			}
		}

<bpmn2:collaboration id="_Collaboration_2" name="Handle a patient general reception">
    <bpmn2:participant id="Patient" name="Patient" processRef="CP1"/>
    <bpmn2:participant id="Participant_1" name="Receptionist" processRef="R"/>
    <bpmn2:messageFlow id="MessageFlow_3" name="Request for appointment" sourceRef="SendTask_2" targetRef="ReceiveTask_4"/>
    <bpmn2:messageFlow id="MessageFlow_5" name="Information to visit specialist" sourceRef="SendTask_3" targetRef="ReceiveTask_2"/>
    <bpmn2:messageFlow id="MessageFlow_2" name="Information to visit cancer detection unit" sourceRef="SendTask_4" targetRef="ReceiveTask_1"/>
    <bpmn2:messageFlow id="MessageFlow_6" name="Appointment made" sourceRef="ReceiveTask_5" targetRef="SendTask_1"/>
    <bpmn2:messageFlow id="MessageFlow_4" name="Patient transfer to emergency" sourceRef="SendTask_5" targetRef="ReceiveTask_3"/>
    <bpmn2:messageFlow id="MessageFlow_1" name="Request for appointment by phone" sourceRef="SendTask_1" targetRef="ReceiveTask_5"/>
  </bpmn2:collaboration>