/*
* Copyright 2002-2009 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.concurrent.Callable;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.RejectedExecutionException;
import org.springframework.core.task.TaskRejectedException;
import org.springframework.core.task.support.TaskExecutorAdapter;
import org.springframework.scheduling.SchedulingTaskExecutor;
/**
* Adapter that takes a JDK 1.5 <code>java.util.concurrent.Executor</code> and
* exposes a Spring {@link org.springframework.core.task.TaskExecutor} for it.
* Also detects an extended <code>java.util.concurrent.ExecutorService</code>, adapting
* the {@link org.springframework.core.task.AsyncTaskExecutor} interface accordingly.
*
* <p>Note that there is a pre-built {@link ThreadPoolTaskExecutor} that allows for
* defining a JDK 1.5 {@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 ThreadPoolTaskExecutor
*/
public class ConcurrentTaskExecutor implements SchedulingTaskExecutor {
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 JDK 1.5 concurrent executor.
* @param concurrentExecutor the JDK 1.5 concurrent executor to delegate to
*/
public ConcurrentTaskExecutor(Executor concurrentExecutor) {
setConcurrentExecutor(concurrentExecutor);
}
/**
* Specify the JDK 1.5 concurrent executor to delegate to.
*/
public final void setConcurrentExecutor(Executor concurrentExecutor) {
this.concurrentExecutor =
(concurrentExecutor != null ? concurrentExecutor : Executors.newSingleThreadExecutor());
this.adaptedExecutor = new TaskExecutorAdapter(this.concurrentExecutor);
}
/**
* Return the JDK 1.5 concurrent executor that this adapter delegates to.
*/
public final Executor getConcurrentExecutor() {
return this.concurrentExecutor;
}
public void execute(Runnable task) {
this.adaptedExecutor.execute(task);
}
public void execute(Runnable task, long startTimeout) {
this.adaptedExecutor.execute(task, startTimeout);
}
public Future<?> submit(Runnable task) {
return this.adaptedExecutor.submit(task);
}
public <T> Future<T> submit(Callable<T> task) {
return this.adaptedExecutor.submit(task);
}
/**
* This task executor prefers short-lived work units.
*/
public boolean prefersShortLivedTasks() {
return true;
}
}
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