4.17. User Task calls

The User Task service exposes a Java API for managing the life cycle of its User Tasks via the TaskClient class. The API is intended for developers to allow direct managing of the lifecycle of User Tasks. End users are advised to use the Business Central web application for User Task management.

To manage user tasks via a public API use the methods of the org.kie.api.task.TaskService class. The methods of this interface take the following arguments:

  • taskId: ID of the target Task instance usually extracted from the currently selected User Task in the user task list in the user interface
  • userId: ID of the user that is executing the action called by the method; usually the ID of the user that is logged in

The following is a subset of methods provided by the org.kie.api.task.TaskService class: 

void start(long taskId, String userId);
void stop(long taskId, String userId);
void release(long taskId, String userId);
void suspend(long taskId, String userId);
void resume(long taskId, String userId);
void skip(long taskId, String userId);
void delegate(long taskId, String userId, String targetUserId);
void complete(long taskId, String userId, Map<String, Object> results);

Example 4.9. Starting and completing a simple user task

import org.kie.api.runtime.KieSession;
import org.kie.api.runtime.manager.RuntimeEngine;
import org.kie.api.runtime.manager.RuntimeManager;
import org.kie.api.runtime.process.ProcessInstance;
import org.kie.api.task.TaskService;
import org.kie.api.task.model.TaskSummary;

....
KieSession ksession = runtimeEngine.getKieSession();
TaskService taskService = runtimeEngine.getTaskService();
ProcessInstance processInstance = ksession.startProcess("com.sample.bpmn.hello");

// John is assigned a task and he completes it
List<TaskSummary> list = taskService.getTasksAssignedAsPotentialOwner("john", "en-UK");
TaskSummary task = list.get(0);

logger.info("John is executing task {}", task.getName());

taskService.start(task.getId(), "john");
taskService.complete(task.getId(), "john", null);

...