// see DirectoryScannerMXBean
public void scan() {
final ScanTask task;
synchronized (this) {
final LinkedList<File> list;
switch (state) {
case RUNNING:
case SCHEDULED:
throw new IllegalStateException(state.toString());
case STOPPED:
case COMPLETED:
// only accept to scan if state is STOPPED or COMPLETED.
list = new LinkedList<File>();
list.add(rootFile);
break;
default:
throw new IllegalStateException(String.valueOf(state));
}
// Create a new ScanTask object for our root directory file.
//
currentTask = task = new ScanTask(list, this);
// transient state... will be switched to RUNNING when
// task.execute() is called. This code could in fact be modified
// to use java.util.concurent.Future and, to push the task to
// an executor. We would then need to wait for the task to
// complete before returning. However, this wouldn't buy us
// anything - since this method should wait for the task to
// finish anyway: so why would we do it?
// As it stands, we simply call task.execute() in the current
// thread - brave and fearless readers may want to attempt the
// modification ;-)
//
setStateAndNotify(SCHEDULED);
}
task.execute();
}
