org.springframework.scheduling

## 接口 TaskScheduler

- 所有已知实现类:
    ConcurrentTaskScheduler, DefaultManagedTaskScheduler, ThreadPoolTaskScheduler

      public interface TaskScheduler

  Task scheduler interface that abstracts the scheduling of `Runnables` based on different kinds of triggers.

  This interface is separate from `SchedulingTaskExecutor` since it usually represents for a different kind of backend, i.e. a thread pool with different characteristics and capabilities. Implementations may implement both interfaces if they can handle both kinds of execution characteristics.

  The 'default' implementation is `ThreadPoolTaskScheduler`, wrapping a native `ScheduledExecutorService` and adding extended trigger capabilities.

  This interface is roughly equivalent to a JSR-236 `ManagedScheduledExecutorService` as supported in Java EE 7 environments but aligned with Spring's `TaskExecutor` model.

  从以下版本开始:
    3.0
  作者:
    Juergen Hoeller
  另请参阅:
    `TaskExecutor`, `ScheduledExecutorService`, `ThreadPoolTaskScheduler`

- - ### 方法概要

    所有方法 实例方法 抽象方法 默认方法
    限定符和类型 | 方法和说明
    --- | ---
    `ScheduledFuture<?>` | `schedule(Runnable task, Date startTime)` Schedule the given `Runnable`, invoking it at the specified execution time.
    `default ScheduledFuture<?>` | `schedule(Runnable task, Instant startTime)` Schedule the given `Runnable`, invoking it at the specified execution time.
    `ScheduledFuture<?>` | `schedule(Runnable task, Trigger trigger)` Schedule the given `Runnable`, invoking it whenever the trigger indicates a next execution time.
    `ScheduledFuture<?>` | `scheduleAtFixedRate(Runnable task, Date startTime, long period)` Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given period.
    `default ScheduledFuture<?>` | `scheduleAtFixedRate(Runnable task, Duration period)` Schedule the given `Runnable`, starting as soon as possible and invoking it with the given period.
    `default ScheduledFuture<?>` | `scheduleAtFixedRate(Runnable task, Instant startTime, Duration period)` Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given period.
    `ScheduledFuture<?>` | `scheduleAtFixedRate(Runnable task, long period)` Schedule the given `Runnable`, starting as soon as possible and invoking it with the given period.
    `ScheduledFuture<?>` | `scheduleWithFixedDelay(Runnable task, Date startTime, long delay)` Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given delay between the completion of one execution and the start of the next.
    `default ScheduledFuture<?>` | `scheduleWithFixedDelay(Runnable task, Duration delay)` Schedule the given `Runnable`, starting as soon as possible and invoking it with the given delay between the completion of one execution and the start of the next.
    `default ScheduledFuture<?>` | `scheduleWithFixedDelay(Runnable task, Instant startTime, Duration delay)` Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given delay between the completion of one execution and the start of the next.
    `ScheduledFuture<?>` | `scheduleWithFixedDelay(Runnable task, long delay)` Schedule the given `Runnable`, starting as soon as possible and invoking it with the given delay between the completion of one execution and the start of the next.

- - ### 方法详细资料

    - #### schedule

          @Nullable
          ScheduledFuture<?> schedule(Runnable task,
                                                 Trigger trigger)

      Schedule the given `Runnable`, invoking it whenever the trigger indicates a next execution time.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `trigger` - an implementation of the `Trigger` interface, e.g. a `CronTrigger` object wrapping a cron expression
      返回:
        a `ScheduledFuture` representing pending completion of the task, or `null` if the given Trigger object never fires (i.e. returns `null` from `Trigger.nextExecutionTime(org.springframework.scheduling.TriggerContext)`)
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      另请参阅:
        `CronTrigger`

    - #### schedule

          default ScheduledFuture<?> schedule(Runnable task,
                                              Instant startTime)

      Schedule the given `Runnable`, invoking it at the specified execution time.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      从以下版本开始:
        5.0
      另请参阅:
        `schedule(Runnable, Date)`

    - #### schedule

          ScheduledFuture<?> schedule(Runnable task,
                                      Date startTime)

      Schedule the given `Runnable`, invoking it at the specified execution time.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)

    - #### scheduleAtFixedRate

          default ScheduledFuture<?> scheduleAtFixedRate(Runnable task,
                                                         Instant startTime,
                                                         Duration period)

      Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given period.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired first execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
        `period` - the interval between successive executions of the task
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      从以下版本开始:
        5.0
      另请参阅:
        `scheduleAtFixedRate(Runnable, Date, long)`

    - #### scheduleAtFixedRate

          ScheduledFuture<?> scheduleAtFixedRate(Runnable task,
                                                 Date startTime,
                                                 long period)

      Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given period.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired first execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
        `period` - the interval between successive executions of the task (in milliseconds)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)

    - #### scheduleAtFixedRate

          default ScheduledFuture<?> scheduleAtFixedRate(Runnable task,
                                                         Duration period)

      Schedule the given `Runnable`, starting as soon as possible and invoking it with the given period.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `period` - the interval between successive executions of the task
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      从以下版本开始:
        5.0
      另请参阅:
        `scheduleAtFixedRate(Runnable, long)`

    - #### scheduleAtFixedRate

          ScheduledFuture<?> scheduleAtFixedRate(Runnable task,
                                                 long period)

      Schedule the given `Runnable`, starting as soon as possible and invoking it with the given period.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `period` - the interval between successive executions of the task (in milliseconds)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)

    - #### scheduleWithFixedDelay

          default ScheduledFuture<?> scheduleWithFixedDelay(Runnable task,
                                                            Instant startTime,
                                                            Duration delay)

      Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given delay between the completion of one execution and the start of the next.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired first execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
        `delay` - the delay between the completion of one execution and the start of the next
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      从以下版本开始:
        5.0
      另请参阅:
        `scheduleWithFixedDelay(Runnable, Date, long)`

    - #### scheduleWithFixedDelay

          ScheduledFuture<?> scheduleWithFixedDelay(Runnable task,
                                                    Date startTime,
                                                    long delay)

      Schedule the given `Runnable`, invoking it at the specified execution time and subsequently with the given delay between the completion of one execution and the start of the next.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `startTime` - the desired first execution time for the task (if this is in the past, the task will be executed immediately, i.e. as soon as possible)
        `delay` - the delay between the completion of one execution and the start of the next (in milliseconds)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)

    - #### scheduleWithFixedDelay

          default ScheduledFuture<?> scheduleWithFixedDelay(Runnable task,
                                                            Duration delay)

      Schedule the given `Runnable`, starting as soon as possible and invoking it with the given delay between the completion of one execution and the start of the next.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `delay` - the delay between the completion of one execution and the start of the next
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)
      从以下版本开始:
        5.0
      另请参阅:
        `scheduleWithFixedDelay(Runnable, long)`

    - #### scheduleWithFixedDelay

          ScheduledFuture<?> scheduleWithFixedDelay(Runnable task,
                                                    long delay)

      Schedule the given `Runnable`, starting as soon as possible and invoking it with the given delay between the completion of one execution and the start of the next.

      Execution will end once the scheduler shuts down or the returned `ScheduledFuture` gets cancelled.

      参数:
        `task` - the Runnable to execute whenever the trigger fires
        `delay` - the delay between the completion of one execution and the start of the next (in milliseconds)
      返回:
        a `ScheduledFuture` representing pending completion of the task
      抛出:
        `org.springframework.core.task.TaskRejectedException` - if the given task was not accepted for internal reasons (e.g. a pool overload handling policy or a pool shutdown in progress)