How to get Task Details of a BPM Process using BPM API as a rest full service.

This guide provides instructions on how to get Task Details of a SAP BPM Process using BPM API as a Restful Service.

Applies to:

This Document Holds good for all CE 7.3 SP05 onward. This service can be called from UI5 Screen as an Ajax call.

Please note that from 7.31 SP09 onward you can also use the standard BPM OData service to retrieve task details and complete the task:Custom UIs with the BPM OData Service.

Special Thanks to Christian Loos  for commenting and mentioning Custom UIs with the BPM OData Service & Andre Backofen for the allowing me mention his blog in the document.

Summary:

This guide describes step-by-step how to get Task Details of a BPM Process using BPM API as a rest full service.

About Me:

Piyas Kumar Das

As a Sr. Netweaver Consultant, I’ve been undertaking consulting assignments leveraging on my undermentioned NetWeaver skills.

• Business Process Management (SAP NW BPM)
• Restful Services using BPM api to be used in UI5 Screens.
• SAP Web Dynpro Java (SAP WD4J)
• SAP Business Rules Management (SAP BRMS)
• SAP Composit Application Framework (SAP CAF)
• Master Data Management (SAP NW MDM)
• Enterprise Portal (SAP EP)
• Services creation using NWDS (SAP EJB)
• Enterprise SOA

Prerequisites:

You should have read through the document : How to Start a BPM Process using BPM API as a RESTful service.

We will be discussing following points in detail in this document –

1. Adding Libraries.
2. Setting up the foundation for using Libraries.
3. Creating Deploy-able Object.
4. Accessing the methods exposed.
5. Testing your REST services

Adding Libraries:

Step 1 : Refer the document to add libraries.

Setting up the foundation for using Library:

Step 1 to Step 4 is same as mentioned in the document.

Step 5 : Create a restful service class file and write a code as shown below or if you are continuing from the document then just copy past the methods only.

import java.io.StringReader;
import java.net.URI;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;
import bo.Material;
import bo.MaterialCreation;
import bo.TaskHeader;
import bo.TaskHeaders;
import com.sap.bpm.api.BPMFactory;
import com.sap.bpm.exception.api.BPMException;
import com.sap.bpm.pm.api.ProcessDefinition;
import com.sap.bpm.pm.api.ProcessDefinitionManager;
import com.sap.bpm.pm.api.ProcessStartEvent;
import com.sap.bpm.pm.api.ProcessStartManager;
import com.sap.bpm.tm.api.Status;
import com.sap.bpm.tm.api.TaskAbstract;
import com.sap.bpm.tm.api.TaskDetail;
import com.sap.bpm.tm.api.TaskInstanceManager;
import com.sap.tc.logging.Location;
import commonj.sdo.DataObject;
import commonj.sdo.helper.XMLHelper;
@Path("/MaterialCreationService")
@Produces({MediaType.APPLICATION_XML})
public class MaterialCreationToRestService {
  private static final Location location = Location.getLocation(MaterialCreationToRestService.class);
  private final String PRE_TASK_URI = "bpm://bpm.sap.com/task-instance/";
  @Path("/getTaskDetails/{task-id}")
  @GET
  @Consumes({MediaType.APPLICATION_JSON})
  @Produces({MediaType.APPLICATION_JSON})
  public Material getTaskDetails(@PathParam("task-id") String taskInstanceId) throws Exception
  {
  System.err.println("MaterialMaintenanceService -> getTaskDetails Task ID: "+taskInstanceId);
  taskInstanceId = PRE_TASK_URI + taskInstanceId;
  Material material = null;
  try
  {
  //Retrieve the TaskInstanceManager
  TaskInstanceManager taskInstanceManager = BPMFactory.getTaskInstanceManager();
  URI taskInstId = new URI(taskInstanceId);
  TaskDetail taskDetails = taskInstanceManager.getTaskDetail(taskInstId);
  String inputData = XMLHelper.INSTANCE.save(taskDetails.getInputDataObject(), "", "InputData");
  String outputData = XMLHelper.INSTANCE.save(taskDetails.getOutputDataObject(), "", "OutputData");
  System.err.println("InputData : "+inputData);
  System.err.println("OutputData : "+outputData);
  material = convertDocumentToMaterial(inputData);
  }
  catch (Exception e)
  {
  System.err.println(e);
  throw e;
  }
  return material;
  }
  private static void printNodes(Node node)
  {
  for (int i = 0; i < node.getChildNodes().getLength(); i++)
  {
  Node childNode = node.getChildNodes().item(i);
   
        if(childNode.getNodeType() == Node.ELEMENT_NODE)
        {
        if(hasChildNodes(childNode))
        {
        printNodes(childNode);
        }
        else
        {
        System.err.println("Key" + childNode.getNodeName());
        System.err.println("Value" +childNode.getTextContent());
        }
        }
  }
  }
  private static boolean hasChildNodes(Node node)
  {
  int nodeCount = 0;
  for (int i = 0; i < node.getChildNodes().getLength(); i++)
  {
  Node childNode = node.getChildNodes().item(i);
  if(childNode.getNodeType() == Node.ELEMENT_NODE)
  {
  nodeCount++;
  }
  }
  if(nodeCount > 0)
  return true;
  else
  return false;
  }
  private Material convertDocumentToMaterial(String inputData)
  {
  Material material = new Material();
  try
  {
  DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
  DocumentBuilder db = dbf.newDocumentBuilder();
  Document document = db.parse(new InputSource(new StringReader(inputData)));
  document.getDocumentElement().normalize();
  Node pNode = document.getChildNodes().item(0);
  Element pElement = (Element) pNode;
  //Set material data
  material.setMaterial(pElement.getElementsByTagName("ns1:Material").item(0).getTextContent());
  material.setIndustrySector(pElement.getElementsByTagName("ns1:IndustrySector").item(0).getTextContent());
  material.setMaterialType(pElement.getElementsByTagName("ns1:MaterialType").item(0).getTextContent());
  material.setDescription(pElement.getElementsByTagName("ns1:Description").item(0).getTextContent());
  }catch (Exception e)
  {
  System.err.println(e);
  }
  return material;
  }
}

• The Following code is very important as the key value printed in the logs is the key to be used while writing into the “convertDocumentToMaterial” method.

Step 6 & Step 7 is same as mentioned in the document. If you are continuing then you can ignore these steps.

Creating Deploy-able Object & Accessing the methods exposed.

Refer the document to “Creating Deploy-able Object” & “Accessing the methods exposed” as it is the same.

Testing your REST services

You can test the created REST services using the POSTMAN for Chrome or Advanced REST client for Chrome.