vSphere SDK createScheduledTask problems in java

Hi,

I am trying to use vsphere sdk 6 to create scheduled task to unmap datastore, here is the code:

sc: ServiceContent

hostStorageSystem: HostStorageSystem

vmfsUuid: String (the vmfsUuid of a specific datastore)

ManagedObjectReference scheduledTaskManager = sc.getScheduledTaskManager();  // get the scheduledTaskManager

//set methodAction
MethodAction methodAction = new MethodAction();

methodAction.setName("UnmapVmfsVolumeEx_Task");

List<MethodActionArgument> arguments = methodAction.getArgument();

MethodActionArgument arg0 = new MethodActionArgument();

MethodActionArgument arg1 = new MethodActionArgument();

List<String> uuidList = new ArrayList<String>();    

uuidList.add(vmfsUuid);

arg0.setValue(uuidList);

arguments.add(arg0);

//set taskScheduler
OnceTaskScheduler taskScheduler = new OnceTaskScheduler();

//set scheduledTaskSpec

ScheduledTaskSpec taskSpec = new ScheduledTaskInfo();

taskSpec.setName("ScheduledUnmapTask");

taskSpec.setDescription("scheduled task to unmap a datastore");

taskSpec.setEnabled(true);

taskSpec.setAction(methodAction);

taskSpec.setScheduler(taskScheduler);

  _vimPort.createObjectScheduledTask(scheduledTaskManager, hostStorageSystem, taskSpec);

for the unmapVmfsVolumEx_task, I need to pass the a list containing vmfsuuids. But there are problem with arraylist type.

Anyone can help to solve the problem. Not sure whether there are other problems of the above code.