1. Developing SOA Applications with Oracle SOA Suite
  2. Using the Human Workflow Service Component
  3. Building a Custom Worklist Client
  4. Introduction to Building Clients for Workflow Services

Introduction to Building Clients for Workflow Services

When creating a Java client application to call Human Workflow service, ensure that JRF is running on the same environment as the Java client application.

To build a simple worklist application:

The typical sequence of calls when building a simple worklist application is as follows.

  1. Get a handle to IWorklistServiceClient from WorkflowServiceClientFactory.
  2. Get a handle to ITaskQueryService from IWorklistServiceClient.
  3. Authenticate a user by passing a username and password to the authenticate method on ITaskQueryService. Get a handle to IWorkflowContext.
  4. Query the list of tasks using ITaskQueryService.
  5. Get a handle to ITaskService from IWorklistServiceClient.
  6. Iterate over the list of tasks returned, performing actions on the tasks using ITaskService.

The code sample below demonstrates how to build a client for workflow services. A list of all tasks assigned to jstein is queried. A task whose outcome has not been set is approved. 

try
{
 //Create JAVA WorflowServiceClient
 IWorkflowServiceClient  wfSvcClient = WorkflowServiceClientFactory.getWorkflowServiceClient(
  WorkflowServiceClientFactory.REMOTE_CLIENT);
 //Get the task query service
 ITaskQueryService querySvc = wfSvcClient.getTaskQueryService();

 //Login as jstein
 IWorkflowContext ctx = querySvc.authenticate("jstein","welcome1".toCharArry(),null);
 //Set up list of columns to query
 List queryColumns = new ArrayList();
 queryColumns.add("TASKID");
 queryColumns.add("TASKNUMBER");
 queryColumns.add("TITLE");
 queryColumns.add("OUTCOME");
 
 //Query a list of tasks assigned to jstein
 List tasks = querySvc.queryTasks(ctx,
              queryColumns,                   
              null, //Do not query additional info
              ITaskQueryService.AssignmentFilter.MY,
              null, //No keywords
              null, //No custom predicate
              null, //No special ordering
              0,    //Do not page the query result
              0);
 //Get the task service
 ITaskService taskSvc = wfSvcClient.getTaskService();
 //Loop over the tasks, outputting task information, and approving any
 //tasks whose outcome has not been set...
 for(int i = 0 ; i < tasks.size() ; i ++)
 {
  Task task = (Task)tasks.get(i);
  int taskNumber = task.getSystemAttributes().getTaskNumber();
  String title = task.getTitle();
  String taskId = task.getSystemAttributes().getTaskId();
  String outcome = task.getSystemAttributes().getOutcome();
  if(outcome == null)
  {
   outcome = "APPROVE";
   taskSvc.updateTaskOutcome(ctx,taskId,outcome);
  }
  System.out.println("Task #"+taskNumber+" ("+title+") is "+outcome);
 }

}
catch (Exception e)
{
 //Handle any exceptions raised here...
 System.out.println("Caught workflow exception: "+e.getMessage());
}