/*
* 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.HashMap;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import javax.enterprise.concurrent.ManagedExecutors;
import javax.enterprise.concurrent.ManagedTask;
import org.springframework.core.task.AsyncListenableTaskExecutor;
import org.springframework.core.task.support.TaskExecutorAdapter;
import org.springframework.scheduling.SchedulingAwareRunnable;
import org.springframework.scheduling.SchedulingTaskExecutor;
import org.springframework.util.ClassUtils;
import org.springframework.util.concurrent.ListenableFuture;
/**
* Adapter that takes a {@code java.util.concurrent.Executor} and exposes
* a Spring {@link org.springframework.core.task.TaskExecutor} for it.
* Also detects an extended {@code java.util.concurrent.ExecutorService}, adapting
* the {@link org.springframework.core.task.AsyncTaskExecutor} interface accordingly.
*
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedExecutorService}
* in order to expose {@link javax.enterprise.concurrent.ManagedTask} adapters for it,
* exposing a long-running hint based on {@link SchedulingAwareRunnable} and an identity
* name based on the given Runnable/Callable's {@code toString()}. For JSR-236 style
* lookup in a Java EE 7 environment, consider using {@link DefaultManagedTaskExecutor}.
*
* <p>Note that there is a pre-built {@link ThreadPoolTaskExecutor} that allows
* for defining a {@link java.util.concurrent.ThreadPoolExecutor} in bean style,
* exposing it as a Spring {@link org.springframework.core.task.TaskExecutor} directly.
* This is a convenient alternative to a raw ThreadPoolExecutor definition with
* a separate definition of the present adapter class.
*
* @author Juergen Hoeller
* @since 2.0
* @see java.util.concurrent.Executor
* @see java.util.concurrent.ExecutorService
* @see java.util.concurrent.ThreadPoolExecutor
* @see java.util.concurrent.Executors
* @see DefaultManagedTaskExecutor
* @see ThreadPoolTaskExecutor
*/
public class ConcurrentTaskExecutor implements AsyncListenableTaskExecutor, SchedulingTaskExecutor {
private static Class<?> managedExecutorServiceClass;
static {
try {
managedExecutorServiceClass = ClassUtils.forName(
"javax.enterprise.concurrent.ManagedExecutorService",
ConcurrentTaskScheduler.class.getClassLoader());
}
catch (ClassNotFoundException ex) {
// JSR-236 API not available...
managedExecutorServiceClass = null;
}
}
private Executor concurrentExecutor;
private TaskExecutorAdapter adaptedExecutor;
/**
* Create a new ConcurrentTaskExecutor, using a single thread executor as default.
* @see java.util.concurrent.Executors#newSingleThreadExecutor()
*/
public ConcurrentTaskExecutor() {
setConcurrentExecutor(null);
}
/**
* Create a new ConcurrentTaskExecutor, using the given {@link java.util.concurrent.Executor}.
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedExecutorService}
* in order to expose {@link javax.enterprise.concurrent.ManagedTask} adapters for it.
* @param concurrentExecutor the {@link java.util.concurrent.Executor} to delegate to
*/
public ConcurrentTaskExecutor(Executor concurrentExecutor) {
setConcurrentExecutor(concurrentExecutor);
}
/**
* Specify the {@link java.util.concurrent.Executor} to delegate to.
* <p>Autodetects a JSR-236 {@link javax.enterprise.concurrent.ManagedExecutorService}
* in order to expose {@link javax.enterprise.concurrent.ManagedTask} adapters for it.
*/
public final void setConcurrentExecutor(Executor concurrentExecutor) {
if (concurrentExecutor != null) {
this.concurrentExecutor = concurrentExecutor;
if (managedExecutorServiceClass != null && managedExecutorServiceClass.isInstance(concurrentExecutor)) {
this.adaptedExecutor = new ManagedTaskExecutorAdapter(concurrentExecutor);
}
else {
this.adaptedExecutor = new TaskExecutorAdapter(concurrentExecutor);
}
}
else {
this.concurrentExecutor = Executors.newSingleThreadExecutor();
this.adaptedExecutor = new TaskExecutorAdapter(this.concurrentExecutor);
}
}
/**
* Return the {@link java.util.concurrent.Executor} that this adapter delegates to.
*/
public final Executor getConcurrentExecutor() {
return this.concurrentExecutor;
}
@Override
public void execute(Runnable task) {
this.adaptedExecutor.execute(task);
}
@Override
public void execute(Runnable task, long startTimeout) {
this.adaptedExecutor.execute(task, startTimeout);
}
@Override
public Future<?> submit(Runnable task) {
return this.adaptedExecutor.submit(task);
}
@Override
public <T> Future<T> submit(Callable<T> task) {
return this.adaptedExecutor.submit(task);
}
@Override
public ListenableFuture<?> submitListenable(Runnable task) {
return this.adaptedExecutor.submitListenable(task);
}
@Override
public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
return this.adaptedExecutor.submitListenable(task);
}
/**
* This task executor prefers short-lived work units.
*/
@Override
public boolean prefersShortLivedTasks() {
return true;
}
/**
* TaskExecutorAdapter subclass that wraps all provided Runnables and Callables
* with a JSR-236 ManagedTask, exposing a long-running hint based on
* {@link SchedulingAwareRunnable} and an identity name based on the task's
* {@code toString()} representation.
*/
private static class ManagedTaskExecutorAdapter extends TaskExecutorAdapter {
public ManagedTaskExecutorAdapter(Executor concurrentExecutor) {
super(concurrentExecutor);
}
@Override
public void execute(Runnable task) {
super.execute(ManagedTaskBuilder.buildManagedTask(task, task.toString()));
}
@Override
public Future<?> submit(Runnable task) {
return super.submit(ManagedTaskBuilder.buildManagedTask(task, task.toString()));
}
@Override
public <T> Future<T> submit(Callable<T> task) {
return super.submit(ManagedTaskBuilder.buildManagedTask(task, task.toString()));
}
@Override
public ListenableFuture<?> submitListenable(Runnable task) {
return super.submitListenable(ManagedTaskBuilder.buildManagedTask(task, task.toString()));
}
@Override
public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
return super.submitListenable(ManagedTaskBuilder.buildManagedTask(task, task.toString()));
}
}
/**
* Delegate that wraps a given Runnable/Callable with a JSR-236 ManagedTask,
* exposing a long-running hint based on {@link SchedulingAwareRunnable}
* and a given identity name.
*/
protected static class ManagedTaskBuilder {
public static Runnable buildManagedTask(Runnable task, String identityName) {
Map<String, String> properties = new HashMap<String, String>(2);
if (task instanceof SchedulingAwareRunnable) {
properties.put(ManagedTask.LONGRUNNING_HINT,
Boolean.toString(((SchedulingAwareRunnable) task).isLongLived()));
}
properties.put(ManagedTask.IDENTITY_NAME, identityName);
return ManagedExecutors.managedTask(task, properties, null);
}
public static <T> Callable<T> buildManagedTask(Callable<T> task, String identityName) {
Map<String, String> properties = new HashMap<String, String>(1);
properties.put(ManagedTask.IDENTITY_NAME, identityName);
return ManagedExecutors.managedTask(task, properties, null);
}
}
}