public abstract class AbstractExecutorService extends Object implements ExecutorService
Provides default implementations of ExecutorService execution methods. This class implements the submit, invokeAny and invokeAll methods using a RunnableFuture returned by newTaskFor, which defaults to the FutureTask class provided in this package. For example, the implementation of submit(Runnable) creates an associated RunnableFuture that is executed and returned. Subclasses may override the newTaskFor methods to return RunnableFuture implementations other than FutureTask.
Extension example. Here is a sketch of a class that customizes ThreadPoolExecutor to use a CustomTask class instead of the default FutureTask:
public class CustomThreadPoolExecutor extends ThreadPoolExecutor {
static class CustomTask<V> implements RunnableFuture<V> {...}
protected <V> RunnableFuture<V> newTaskFor(Callable<V> c) {
return new CustomTask<V>(c);
}
protected <V> RunnableFuture<V> newTaskFor(Runnable r, V v) {
return new CustomTask<V>(r, v);
}
// ... add constructors, etc.
}
public AbstractExecutorService()
protected <T> RunnableFuture<T> newTaskFor(Runnable runnable,
T value) Returns a RunnableFuture for the given runnable and default value.
T - the type of the given valuerunnable - the runnable task being wrappedvalue - the default value for the returned futureRunnableFuture which, when run, will run the underlying runnable and which, as a Future, will yield the given value as its result and provide for cancellation of the underlying taskprotected <T> RunnableFuture<T> newTaskFor(Callable<T> callable)
Returns a RunnableFuture for the given callable task.
T - the type of the callable's resultcallable - the callable task being wrappedRunnableFuture which, when run, will call the underlying callable and which, as a Future, will yield the callable's result as its result and provide for cancellation of the underlying taskpublic Future<?> submit(Runnable task)
Description copied from interface: ExecutorService
Submits a Runnable task for execution and returns a Future representing that task. The Future's get method will return null upon successful completion.
submit in interface ExecutorService
task - the task to submitRejectedExecutionException - if the task cannot be scheduled for executionNullPointerException - if the task is nullpublic <T> Future<T> submit(Runnable task,
T result) Description copied from interface: ExecutorService
Submits a Runnable task for execution and returns a Future representing that task. The Future's get method will return the given result upon successful completion.
submit in interface ExecutorService
T - the type of the resulttask - the task to submitresult - the result to returnRejectedExecutionException - if the task cannot be scheduled for executionNullPointerException - if the task is nullpublic <T> Future<T> submit(Callable<T> task)
Description copied from interface: ExecutorService
Submits a value-returning task for execution and returns a Future representing the pending results of the task. The Future's get method will return the task's result upon successful completion.
If you would like to immediately block waiting for a task, you can use constructions of the form result = exec.submit(aCallable).get();
Note: The Executors class includes a set of methods that can convert some other common closure-like objects, for example, PrivilegedAction to Callable form so they can be submitted.
submit in interface ExecutorService
T - the type of the task's resulttask - the task to submitRejectedExecutionException - if the task cannot be scheduled for executionNullPointerException - if the task is nullpublic <T> T invokeAny(Collection<? extends Callable<T>> tasks)
throws InterruptedException,
ExecutionException Description copied from interface: ExecutorService
Executes the given tasks, returning the result of one that has completed successfully (i.e., without throwing an exception), if any do. Upon normal or exceptional return, tasks that have not completed are cancelled. The results of this method are undefined if the given collection is modified while this operation is in progress.
invokeAny in interface ExecutorService
T - the type of the values returned from the taskstasks - the collection of tasksInterruptedException - if interrupted while waitingExecutionException - if no task successfully completespublic <T> T invokeAny(Collection<? extends Callable<T>> tasks,
long timeout,
TimeUnit unit)
throws InterruptedException,
ExecutionException,
TimeoutException Description copied from interface: ExecutorService
Executes the given tasks, returning the result of one that has completed successfully (i.e., without throwing an exception), if any do before the given timeout elapses. Upon normal or exceptional return, tasks that have not completed are cancelled. The results of this method are undefined if the given collection is modified while this operation is in progress.
invokeAny in interface ExecutorService
T - the type of the values returned from the taskstasks - the collection of taskstimeout - the maximum time to waitunit - the time unit of the timeout argumentInterruptedException - if interrupted while waitingExecutionException - if no task successfully completesTimeoutException - if the given timeout elapses before any task successfully completespublic <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
throws InterruptedException Description copied from interface: ExecutorService
Executes the given tasks, returning a list of Futures holding their status and results when all complete. Future.isDone() is true for each element of the returned list. Note that a completed task could have terminated either normally or by throwing an exception. The results of this method are undefined if the given collection is modified while this operation is in progress.
invokeAll in interface ExecutorService
T - the type of the values returned from the taskstasks - the collection of tasksInterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelledpublic <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks,
long timeout,
TimeUnit unit)
throws InterruptedException Description copied from interface: ExecutorService
Executes the given tasks, returning a list of Futures holding their status and results when all complete or the timeout expires, whichever happens first. Future.isDone() is true for each element of the returned list. Upon return, tasks that have not completed are cancelled. Note that a completed task could have terminated either normally or by throwing an exception. The results of this method are undefined if the given collection is modified while this operation is in progress.
invokeAll in interface ExecutorService
T - the type of the values returned from the taskstasks - the collection of taskstimeout - the maximum time to waitunit - the time unit of the timeout argumentInterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled
© 1993–2017, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.