/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.scheduling;
import java.time.Duration;
import java.time.Instant;
import java.util.Date;
import java.util.concurrent.ScheduledFuture;
/**
* Task scheduler interface that abstracts the scheduling of
* {@link Runnable Runnables} based on different kinds of triggers.
*
* <p>This interface is separate from {@link 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.
*
* <p>The 'default' implementation is
* {@link org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler},
* wrapping a native {@link java.util.concurrent.ScheduledExecutorService}
* and adding extended trigger capabilities.
*
* <p>This interface is roughly equivalent to a JSR-236
* {@code ManagedScheduledExecutorService} as supported in Java EE 7
* environments but aligned with Spring's {@code TaskExecutor} model.
*
* @author Juergen Hoeller
* @since 3.0
* @see org.springframework.core.task.TaskExecutor
* @see java.util.concurrent.ScheduledExecutorService
* @see org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler
*/
public interface TaskScheduler {
/**
* Schedule the given {@link Runnable}, invoking it whenever the trigger
* indicates a next execution time.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param trigger an implementation of the {@link Trigger} interface,
* e.g. a {@link org.springframework.scheduling.support.CronTrigger} object
* wrapping a cron expression
* @return a {@link ScheduledFuture} representing pending completion of the task,
* or {@code null} if the given Trigger object never fires (i.e. returns
* {@code null} from {@link Trigger#nextExecutionTime})
* @throws 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)
* @see org.springframework.scheduling.support.CronTrigger
*/
ScheduledFuture<?> schedule(Runnable task, Trigger trigger);
/**
* Schedule the given {@link Runnable}, invoking it at the specified execution time.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
* @since 5.0
* @see #schedule(Runnable, Date)
*/
default ScheduledFuture<?> schedule(Runnable task, Instant startTime) {
return schedule(task, Date.from(startTime));
}
/**
* Schedule the given {@link Runnable}, invoking it at the specified execution time.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
*/
ScheduledFuture<?> schedule(Runnable task, Date startTime);
/**
* Schedule the given {@link Runnable}, invoking it at the specified execution time
* and subsequently with the given period.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @param period the interval between successive executions of the task
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
* @since 5.0
* @see #scheduleAtFixedRate(Runnable, Date, long)
*/
default ScheduledFuture<?> scheduleAtFixedRate(Runnable task, Instant startTime, Duration period) {
return scheduleAtFixedRate(task, Date.from(startTime), period.toMillis());
}
/**
* Schedule the given {@link Runnable}, invoking it at the specified execution time
* and subsequently with the given period.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @param period the interval between successive executions of the task (in milliseconds)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
*/
ScheduledFuture<?> scheduleAtFixedRate(Runnable task, Date startTime, long period);
/**
* Schedule the given {@link Runnable}, starting as soon as possible and
* invoking it with the given period.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param period the interval between successive executions of the task
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
* @since 5.0
* @see #scheduleAtFixedRate(Runnable, long)
*/
default ScheduledFuture<?> scheduleAtFixedRate(Runnable task, Duration period) {
return scheduleAtFixedRate(task, period.toMillis());
}
/**
* Schedule the given {@link Runnable}, starting as soon as possible and
* invoking it with the given period.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param period the interval between successive executions of the task (in milliseconds)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
*/
ScheduledFuture<?> scheduleAtFixedRate(Runnable task, long period);
/**
* Schedule the given {@link 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.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @param delay the delay between the completion of one execution and the start of the next
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
* @since 5.0
* @see #scheduleWithFixedDelay(Runnable, Date, long)
*/
default ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, Instant startTime, Duration delay) {
return scheduleWithFixedDelay(task, Date.from(startTime), delay.toMillis());
}
/**
* Schedule the given {@link 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.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param 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)
* @param delay the delay between the completion of one execution and the start of the next
* (in milliseconds)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
*/
ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, Date startTime, long delay);
/**
* Schedule the given {@link 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.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param delay the delay between the completion of one execution and the start of the next
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
* @since 5.0
* @see #scheduleWithFixedDelay(Runnable, long)
*/
default ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, Duration delay) {
return scheduleWithFixedDelay(task, delay.toMillis());
}
/**
* Schedule the given {@link 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.
* <p>Execution will end once the scheduler shuts down or the returned
* {@link ScheduledFuture} gets cancelled.
* @param task the Runnable to execute whenever the trigger fires
* @param delay the delay between the completion of one execution and the start of the next
* (in milliseconds)
* @return a {@link ScheduledFuture} representing pending completion of the task
* @throws 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)
*/
ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, long delay);
}