问app engine开发任务未运行

EN

public class BackupMaker
{

    public BackupMaker(String task_handler_url, String task_queue_name,
            String task_name)
    {
        final Queue q = (task_queue_name == null) ? QueueFactory
                .getDefaultQueue() : QueueFactory.getQueue(task_queue_name);
        final TaskOptions task = TaskOptions.Builder.withUrl(task_handler_url)
                .taskName(task_name);
        q.add(task);
    }
}

public class BackupMakerTaskEntry extends HttpServlet
{

    private static final long   serialVersionUID    = 1L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException
    {
        System.out.println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Task is running !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
        res.getWriter().print("hello!");
    }
}

private void create_backup_task()
{
    final String task_handler_url = "/data_backup/task_entry";
    final String task_queue_name = null; // Use 'Default' queue.
    final String task_name = "Test";
    new BackupMaker(task_handler_url, task_queue_name, task_name);
}