| java.lang.Object
 java.util.concurrent.AbstractExecutorService
java.util.concurrent.ThreadPoolExecutor
java.util.concurrent.ScheduledThreadPoolExecutor
| ScheduledThreadPoolExecutor | | public class ScheduledThreadPoolExecutor extends ThreadPoolExecutor implements ScheduledExecutorService(Code) | | A
ThreadPoolExecutor that can additionally schedule
commands to run after a given delay, or to execute
periodically. This class is preferable to
java.util.Timer when multiple worker threads are needed, or when the additional
flexibility or capabilities of
ThreadPoolExecutor (which
this class extends) are required.
Delayed tasks execute no sooner than they are enabled, but
without any real-time guarantees about when, after they are
enabled, they will commence. Tasks scheduled for exactly the same
execution time are enabled in first-in-first-out (FIFO) order of
submission.
While this class inherits from
ThreadPoolExecutor , a few
of the inherited tuning methods are not useful for it. In
particular, because it acts as a fixed-sized pool using
corePoolSize threads and an unbounded queue, adjustments
to maximumPoolSize have no useful effect.
since:
1.5
author:
Doug Lea |
| Constructor Summary | |
| public | ScheduledThreadPoolExecutor(int corePoolSize)
Creates a new ScheduledThreadPoolExecutor with the given core
pool size. | | public | ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory)
Creates a new ScheduledThreadPoolExecutor with the given
initial parameters.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
Parameters:
threadFactory - the factory to use when the executorcreates a new thread. | | public | ScheduledThreadPoolExecutor(int corePoolSize, RejectedExecutionHandler handler)
Creates a new ScheduledThreadPoolExecutor with the given
initial parameters. | | public | ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory, RejectedExecutionHandler handler)
Creates a new ScheduledThreadPoolExecutor with the given
initial parameters.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
Parameters:
threadFactory - the factory to use when the executorcreates a new thread. |
| Method Summary | |
| public void | execute(Runnable command)
Execute command with zero required delay. | | public boolean | getContinueExistingPeriodicTasksAfterShutdownPolicy()
Get the policy on whether to continue executing existing
periodic tasks even when this executor has been
shutdown. | | public boolean | getExecuteExistingDelayedTasksAfterShutdownPolicy()
Get policy on whether to execute existing delayed
tasks even when this executor has been shutdown. | | public BlockingQueue<Runnable> | getQueue()
Returns the task queue used by this executor. | | final long | now()
| | public boolean | remove(Runnable task)
| | public ScheduledFuture | schedule(Runnable command, long delay, TimeUnit unit)
| | public ScheduledFuture<V> | schedule(Callable<V> callable, long delay, TimeUnit unit)
| | public ScheduledFuture | scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit)
| | public ScheduledFuture | scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit)
| | public void | setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean value)
Set policy on whether to continue executing existing periodic
tasks even when this executor has been shutdown. | | public void | setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean value)
Set policy on whether to execute existing delayed
tasks even when this executor has been shutdown. | | public void | shutdown()
Initiates an orderly shutdown in which previously submitted
tasks are executed, but no new tasks will be accepted. | | public List<Runnable> | shutdownNow()
Attempts to stop all actively executing tasks, halts the
processing of waiting tasks, and returns a list of the tasks that were
awaiting execution. | | public Future | submit(Runnable task)
| | public Future<T> | submit(Runnable task, T result)
| | public Future<T> | submit(Callable<T> task)
|
| ScheduledThreadPoolExecutor | | public ScheduledThreadPoolExecutor(int corePoolSize)(Code) | | Creates a new ScheduledThreadPoolExecutor with the given core
pool size.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
throws:
IllegalArgumentException - if corePoolSize less than orequal to zero |
| ScheduledThreadPoolExecutor | | public ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory)(Code) | | Creates a new ScheduledThreadPoolExecutor with the given
initial parameters.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
Parameters:
threadFactory - the factory to use when the executorcreates a new thread.
throws:
NullPointerException - if threadFactory is null |
| ScheduledThreadPoolExecutor | | public ScheduledThreadPoolExecutor(int corePoolSize, RejectedExecutionHandler handler)(Code) | | Creates a new ScheduledThreadPoolExecutor with the given
initial parameters.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
Parameters:
handler - the handler to use when execution is blockedbecause the thread bounds and queue capacities are reached.
throws:
NullPointerException - if handler is null |
| ScheduledThreadPoolExecutor | | public ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory, RejectedExecutionHandler handler)(Code) | | Creates a new ScheduledThreadPoolExecutor with the given
initial parameters.
Parameters:
corePoolSize - the number of threads to keep in the pool,even if they are idle.
Parameters:
threadFactory - the factory to use when the executorcreates a new thread.
Parameters:
handler - the handler to use when execution is blockedbecause the thread bounds and queue capacities are reached.
throws:
NullPointerException - if threadFactory or handler is null |
| execute | | public void execute(Runnable command)(Code) | | Execute command with zero required delay. This has effect
equivalent to schedule(command, 0, anyUnit). Note
that inspections of the queue and of the list returned by
shutdownNow will access the zero-delayed
ScheduledFuture , not the command itself.
Parameters:
command - the task to execute
throws:
RejectedExecutionException - at discretion ofRejectedExecutionHandler, if task cannot be acceptedfor execution because the executor has been shut down.
throws:
NullPointerException - if command is null |
| getContinueExistingPeriodicTasksAfterShutdownPolicy | | public boolean getContinueExistingPeriodicTasksAfterShutdownPolicy()(Code) | | Get the policy on whether to continue executing existing
periodic tasks even when this executor has been
shutdown. In this case, these tasks will only
terminate upon shutdownNow or after setting the policy
to false when already shutdown. This value is by
default false.
true if will continue after shutdown.
See Also: ScheduledThreadPoolExecutor.setContinueExistingPeriodicTasksAfterShutdownPolicy |
| getExecuteExistingDelayedTasksAfterShutdownPolicy | | public boolean getExecuteExistingDelayedTasksAfterShutdownPolicy()(Code) | | Get policy on whether to execute existing delayed
tasks even when this executor has been shutdown. In
this case, these tasks will only terminate upon
shutdownNow, or after setting the policy to
false when already shutdown. This value is by default
true.
true if will execute after shutdown.
See Also: ScheduledThreadPoolExecutor.setExecuteExistingDelayedTasksAfterShutdownPolicy |
| getQueue | | public BlockingQueue<Runnable> getQueue()(Code) | | Returns the task queue used by this executor. Each element of
this queue is a
ScheduledFuture , including those
tasks submitted using execute which are for scheduling
purposes used as the basis of a zero-delay
ScheduledFuture. Iteration over this queue is
not guaranteed to traverse tasks in the order in
which they will execute.
the task queue |
| now | | final long now()(Code) | | Returns nanosecond time offset by origin
|
| setContinueExistingPeriodicTasksAfterShutdownPolicy | | public void setContinueExistingPeriodicTasksAfterShutdownPolicy(boolean value)(Code) | | Set policy on whether to continue executing existing periodic
tasks even when this executor has been shutdown. In
this case, these tasks will only terminate upon
shutdownNow, or after setting the policy to
false when already shutdown. This value is by default
false.
Parameters:
value - if true, continue after shutdown, else don't.
See Also: ScheduledThreadPoolExecutor.getExecuteExistingDelayedTasksAfterShutdownPolicy |
| setExecuteExistingDelayedTasksAfterShutdownPolicy | | public void setExecuteExistingDelayedTasksAfterShutdownPolicy(boolean value)(Code) | | Set policy on whether to execute existing delayed
tasks even when this executor has been shutdown. In
this case, these tasks will only terminate upon
shutdownNow, or after setting the policy to
false when already shutdown. This value is by default
true.
Parameters:
value - if true, execute after shutdown, else don't.
See Also: ScheduledThreadPoolExecutor.getExecuteExistingDelayedTasksAfterShutdownPolicy |
| shutdown | | public void shutdown()(Code) | | Initiates an orderly shutdown in which previously submitted
tasks are executed, but no new tasks will be accepted. If the
ExecuteExistingDelayedTasksAfterShutdownPolicy has
been set false, existing delayed tasks whose delays
have not yet elapsed are cancelled. And unless the
ContinueExistingPeriodicTasksAfterShutdownPolicy has
been set true, future executions of existing periodic
tasks will be cancelled.
|
| shutdownNow | | public List<Runnable> shutdownNow()(Code) | | Attempts to stop all actively executing tasks, halts the
processing of waiting tasks, and returns a list of the tasks that were
awaiting execution.
There are no guarantees beyond best-effort attempts to stop
processing actively executing tasks. This implementation
cancels tasks via
Thread.interrupt , so if any tasks mask or
fail to respond to interrupts, they may never terminate.
list of tasks that never commenced execution. Eachelement of this list is a ScheduledFuture,including those tasks submitted using execute, whichare for scheduling purposes used as the basis of a zero-delayScheduledFuture. |
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