/*
* Copyright 2002-2013 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.concurrent;
import java.util.Date;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import javax.enterprise.concurrent.LastExecution;
import javax.enterprise.concurrent.ManagedScheduledExecutorService;
import org.springframework.core.task.TaskRejectedException;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.support.SimpleTriggerContext;
import org.springframework.scheduling.support.TaskUtils;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ErrorHandler;
/**
* Adapter that takes a {@code java.util.concurrent.ScheduledExecutorService} and
* exposes a Spring {@link org.springframework.scheduling.TaskScheduler} for it.
* Extends {@link ConcurrentTaskExecutor} in order to implement the
* {@link org.springframework.scheduling.SchedulingTaskExecutor} interface as well.
*
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedScheduledExecutorService}
* in order to use it for trigger-based scheduling if possible, instead of Spring's
* local trigger management which ends up delegating to regular delay-based scheduling
* against the {@code java.util.concurrent.ScheduledExecutorService} API. For JSR-236 style
* lookup in a Java EE 7 environment, consider using {@link DefaultManagedTaskScheduler}.
*
* <p>Note that there is a pre-built {@link ThreadPoolTaskScheduler} that allows for
* defining a {@link java.util.concurrent.ScheduledThreadPoolExecutor} in bean style,
* exposing it as a Spring {@link org.springframework.scheduling.TaskScheduler} directly.
* This is a convenient alternative to a raw ScheduledThreadPoolExecutor definition with
* a separate definition of the present adapter class.
*
* @author Juergen Hoeller
* @author Mark Fisher
* @since 3.0
* @see java.util.concurrent.ScheduledExecutorService
* @see java.util.concurrent.ScheduledThreadPoolExecutor
* @see java.util.concurrent.Executors
* @see DefaultManagedTaskScheduler
* @see ThreadPoolTaskScheduler
*/
public class ConcurrentTaskScheduler extends ConcurrentTaskExecutor implements TaskScheduler {
private static Class<?> managedScheduledExecutorServiceClass;
static {
try {
managedScheduledExecutorServiceClass = ClassUtils.forName(
"javax.enterprise.concurrent.ManagedScheduledExecutorService",
ConcurrentTaskScheduler.class.getClassLoader());
}
catch (ClassNotFoundException ex) {
// JSR-236 API not available...
managedScheduledExecutorServiceClass = null;
}
}
private ScheduledExecutorService scheduledExecutor;
private boolean enterpriseConcurrentScheduler = false;
private ErrorHandler errorHandler;
/**
* Create a new ConcurrentTaskScheduler,
* using a single thread executor as default.
* @see java.util.concurrent.Executors#newSingleThreadScheduledExecutor()
*/
public ConcurrentTaskScheduler() {
super();
setScheduledExecutor(null);
}
/**
* Create a new ConcurrentTaskScheduler, using the given
* {@link java.util.concurrent.ScheduledExecutorService} as shared delegate.
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedScheduledExecutorService}
* in order to use it for trigger-based scheduling if possible,
* instead of Spring's local trigger management.
* @param scheduledExecutor the {@link java.util.concurrent.ScheduledExecutorService}
* to delegate to for {@link org.springframework.scheduling.SchedulingTaskExecutor}
* as well as {@link TaskScheduler} invocations
*/
public ConcurrentTaskScheduler(ScheduledExecutorService scheduledExecutor) {
super(scheduledExecutor);
setScheduledExecutor(scheduledExecutor);
}
/**
* Create a new ConcurrentTaskScheduler, using the given {@link java.util.concurrent.Executor}
* and {@link java.util.concurrent.ScheduledExecutorService} as delegates.
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedScheduledExecutorService}
* in order to use it for trigger-based scheduling if possible,
* instead of Spring's local trigger management.
* @param concurrentExecutor the {@link java.util.concurrent.Executor} to delegate to
* for {@link org.springframework.scheduling.SchedulingTaskExecutor} invocations
* @param scheduledExecutor the {@link java.util.concurrent.ScheduledExecutorService}
* to delegate to for {@link TaskScheduler} invocations
*/
public ConcurrentTaskScheduler(Executor concurrentExecutor, ScheduledExecutorService scheduledExecutor) {
super(concurrentExecutor);
setScheduledExecutor(scheduledExecutor);
}
/**
* Specify the {@link java.util.concurrent.ScheduledExecutorService} to delegate to.
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedScheduledExecutorService}
* in order to use it for trigger-based scheduling if possible,
* instead of Spring's local trigger management.
* <p>Note: This will only apply to {@link TaskScheduler} invocations.
* If you want the given executor to apply to
* {@link org.springframework.scheduling.SchedulingTaskExecutor} invocations
* as well, pass the same executor reference to {@link #setConcurrentExecutor}.
* @see #setConcurrentExecutor
*/
public final void setScheduledExecutor(ScheduledExecutorService scheduledExecutor) {
if (scheduledExecutor != null) {
this.scheduledExecutor = scheduledExecutor;
this.enterpriseConcurrentScheduler = (managedScheduledExecutorServiceClass != null &&
managedScheduledExecutorServiceClass.isInstance(scheduledExecutor));
}
else {
this.scheduledExecutor = Executors.newSingleThreadScheduledExecutor();
this.enterpriseConcurrentScheduler = false;
}
}
/**
* Provide an {@link ErrorHandler} strategy.
*/
public void setErrorHandler(ErrorHandler errorHandler) {
Assert.notNull(errorHandler, "'errorHandler' must not be null");
this.errorHandler = errorHandler;
}
@Override
public ScheduledFuture<?> schedule(Runnable task, Trigger trigger) {
try {
if (this.enterpriseConcurrentScheduler) {
return new EnterpriseConcurrentTriggerScheduler().schedule(decorateTask(task, true), trigger);
}
else {
ErrorHandler errorHandler = (this.errorHandler != null ? this.errorHandler : TaskUtils.getDefaultErrorHandler(true));
return new ReschedulingRunnable(task, trigger, this.scheduledExecutor, errorHandler).schedule();
}
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
@Override
public ScheduledFuture<?> schedule(Runnable task, Date startTime) {
long initialDelay = startTime.getTime() - System.currentTimeMillis();
try {
return this.scheduledExecutor.schedule(decorateTask(task, false), initialDelay, TimeUnit.MILLISECONDS);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
@Override
public ScheduledFuture<?> scheduleAtFixedRate(Runnable task, Date startTime, long period) {
long initialDelay = startTime.getTime() - System.currentTimeMillis();
try {
return this.scheduledExecutor.scheduleAtFixedRate(decorateTask(task, true), initialDelay, period, TimeUnit.MILLISECONDS);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
@Override
public ScheduledFuture<?> scheduleAtFixedRate(Runnable task, long period) {
try {
return this.scheduledExecutor.scheduleAtFixedRate(decorateTask(task, true), 0, period, TimeUnit.MILLISECONDS);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
@Override
public ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, Date startTime, long delay) {
long initialDelay = startTime.getTime() - System.currentTimeMillis();
try {
return this.scheduledExecutor.scheduleWithFixedDelay(decorateTask(task, true), initialDelay, delay, TimeUnit.MILLISECONDS);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
@Override
public ScheduledFuture<?> scheduleWithFixedDelay(Runnable task, long delay) {
try {
return this.scheduledExecutor.scheduleWithFixedDelay(decorateTask(task, true), 0, delay, TimeUnit.MILLISECONDS);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + this.scheduledExecutor + "] did not accept task: " + task, ex);
}
}
private Runnable decorateTask(Runnable task, boolean isRepeatingTask) {
Runnable result = TaskUtils.decorateTaskWithErrorHandler(task, this.errorHandler, isRepeatingTask);
if (this.enterpriseConcurrentScheduler) {
result = ManagedTaskBuilder.buildManagedTask(result, task.toString());
}
return result;
}
/**
* Delegate that adapts a Spring Trigger to a JSR-236 Trigger.
* Separated into an inner class in order to avoid a hard dependency on the JSR-236 API.
*/
private class EnterpriseConcurrentTriggerScheduler {
public ScheduledFuture<?> schedule(Runnable task, final Trigger trigger) {
ManagedScheduledExecutorService executor = (ManagedScheduledExecutorService) scheduledExecutor;
return executor.schedule(task, new javax.enterprise.concurrent.Trigger() {
@Override
public Date getNextRunTime(LastExecution le, Date taskScheduledTime) {
return trigger.nextExecutionTime(le != null ?
new SimpleTriggerContext(le.getScheduledStart(), le.getRunStart(), le.getRunEnd()) :
new SimpleTriggerContext());
}
@Override
public boolean skipRun(LastExecution lastExecution, Date scheduledRunTime) {
return false;
}
});
}
}
}