Miscellaneous Utilities - The Java Programming Language - page 972

Schedules the given task to execute on a fixed-delay schedule
until cancelled, starting after the given delay , executing every
period milliseconds.
public void scheduleAtFixedRate(TimerTask task, Date firstTime, long
period)
Schedules the given task to execute on a fixed-rate schedule
until cancelled, starting at firstTime , executing every period
milliseconds.
public void scheduleAtFixedRate(TimerTask task, long delay, long
period)
Schedules the given task to execute on a fixed-rate schedule
until cancelled, starting after the given delay , executing every
period milliseconds.
Any time you specify that is in the past schedules an immediate exe-
cution. All times are in millisecondsthe Date class's getTime method con-
verts a Date to milliseconds (see " Time, Dates, and Calendars " on page
695 ) and are approximate because the timer uses THRead.wait(long) to
schedule future executions, and wait , like sleep , does not guarantee pre-
cision. If a delay is so large that adding it to the current time would
cause an overflow, you will get an IllegalArgumentException .
A TimerTask object can only be scheduled with one Timer , and a cancelled
Timer cannot have any new tasks scheduled. If you attempt to schedule
a task that violates either of these restrictions or if you schedule an
already cancelled TimerTask , you will get an IllegalStateException .
A Timer 's thread is subject to the usual thread scheduling of a system
and takes no steps to influence its priority in any wayit is created with
the priority of the thread that created the Timer . If you need to boost
the priority of a given task when it is executing, set the thread prior-
ity within the run method. If you want to boost the priority of the Timer