java.util.concurrent
Class Executors.DelegatedExecutorService

java.lang.Object
  java.util.concurrent.AbstractExecutorService
      java.util.concurrent.Executors.DelegatedExecutorService

All Implemented Interfaces:

Executor, ExecutorService

Direct Known Subclasses:

Executors.DelegatedScheduledExecutorService

Enclosing class:

Executors

static class Executors.DelegatedExecutorService
extends AbstractExecutorService

A wrapper class that exposes only the ExecutorService methods of an implementation.

Constructor Summary

Executors.DelegatedExecutorService(ExecutorService executor)

Method Summary

boolean	awaitTermination(long timeout, TimeUnit unit) Blocks until all tasks have completed execution after a shutdown request, or the timeout occurs, or the current thread is interrupted, whichever happens first.
void	execute(Runnable command) Executes the given command at some time in the future.
<T> List<Future<T>>	invokeAll(Collection<Callable<T>> tasks) Executes the given tasks, returning their results when all complete.
<T> List<Future<T>>	invokeAll(Collection<Callable<T>> tasks, long timeout, TimeUnit unit) Executes the given tasks, returning their results when all complete or the timeout expires, whichever happens first.
<T> T	invokeAny(Collection<Callable<T>> tasks) Executes the given tasks, returning the result of one that has completed successfully (i.e., without throwing an exception), if any do.
<T> T	invokeAny(Collection<Callable<T>> tasks, long timeout, TimeUnit unit) 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.
boolean	isShutdown() Returns true if this executor has been shut down.
boolean	isTerminated() Returns true if all tasks have completed following shut down.
void	shutdown() Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted.
List<Runnable>	shutdownNow() Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution.
<T> Future<T>	submit(Callable<T> task) Submits a value-returning task for execution and returns a Future representing the pending results of the task.
Future<?>	submit(Runnable task) Submits a Runnable task for execution and returns a Future representing that task.
<T> Future<T>	submit(Runnable task, T result) Submits a Runnable task for execution and returns a Future representing that task that will upon completion return the given result.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Executors.DelegatedExecutorService

Executors.DelegatedExecutorService(ExecutorService executor)

Method Detail

execute

public void execute(Runnable command)

Description copied from interface: Executor

Executes the given command at some time in the future. The command may execute in a new thread, in a pooled thread, or in the calling thread, at the discretion of the Executor implementation.

Parameters:

command - the runnable task

shutdown

public void shutdown()

Description copied from interface: ExecutorService

Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be accepted. Invocation has no additional effect if already shut down.

shutdownNow

public List<Runnable> shutdownNow()

Description copied from interface: ExecutorService

Attempts to stop all actively executing tasks, halts the processing of waiting tasks, and returns a list of the tasks that were awaiting execution.

There are no guarantees beyond best-effort attempts to stop processing actively executing tasks. For example, typical implementations will cancel via Thread.interrupt(), so if any tasks mask or fail to respond to interrupts, they may never terminate.

Returns:

list of tasks that never commenced execution

isShutdown

public boolean isShutdown()

Description copied from interface: ExecutorService

Returns true if this executor has been shut down.

Returns:

true if this executor has been shut down

isTerminated

public boolean isTerminated()

Description copied from interface: ExecutorService

Returns true if all tasks have completed following shut down. Note that isTerminated is never true unless either shutdown or shutdownNow was called first.

Returns:

true if all tasks have completed following shut down

awaitTermination

public boolean awaitTermination(long timeout,
                                TimeUnit unit)
                         throws InterruptedException

Description copied from interface: ExecutorService

Blocks until all tasks have completed execution after a shutdown request, or the timeout occurs, or the current thread is interrupted, whichever happens first.

Parameters:

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

true if this executor terminated and false if the timeout elapsed before termination

Throws:

InterruptedException - if interrupted while waiting

submit

public Future<?> submit(Runnable task)

Description copied from interface: ExecutorService

Submits a Runnable task for execution and returns a Future representing that task.

Specified by:

submit in interface ExecutorService

Overrides:

submit in class AbstractExecutorService

Parameters:

task - the task to submit

Returns:

a Future representing pending completion of the task, and whose get() method will return null upon completion.

submit

public <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.

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.

Specified by:

submit in interface ExecutorService

Overrides:

submit in class AbstractExecutorService

Parameters:

task - the task to submit

Returns:

a Future representing pending completion of the task

submit

public <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 that will upon completion return the given result.

Specified by:

submit in interface ExecutorService

Overrides:

submit in class AbstractExecutorService

Parameters:

task - the task to submit

result - the result to return

Returns:

a Future representing pending completion of the task, and whose get() method will return the given result upon completion.

invokeAll

public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks)
                          throws InterruptedException

Description copied from interface: ExecutorService

Executes the given tasks, returning their results when all complete. 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.

Specified by:

invokeAll in interface ExecutorService

Overrides:

invokeAll in class AbstractExecutorService

Parameters:

tasks - the collection of tasks

Returns:

A list of Futures representing the tasks, in the same sequential order as produced by the iterator for the given task list, each of which has completed.

Throws:

InterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled.

invokeAll

public <T> List<Future<T>> invokeAll(Collection<Callable<T>> tasks,
                                     long timeout,
                                     TimeUnit unit)
                          throws InterruptedException

Description copied from interface: ExecutorService

Executes the given tasks, returning their results when all complete or the timeout expires, whichever happens first. 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.

Specified by:

invokeAll in interface ExecutorService

Overrides:

invokeAll in class AbstractExecutorService

Parameters:

tasks - the collection of tasks

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

A list of Futures representing the tasks, in the same sequential order as produced by the iterator for the given task list. If the operation did not time out, each task will have completed. If it did time out, some of thiese tasks will not have completed.

Throws:

InterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled.

invokeAny

public <T> T invokeAny(Collection<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.

Specified by:

invokeAny in interface ExecutorService

Overrides:

invokeAny in class AbstractExecutorService

Parameters:

tasks - the collection of tasks

Returns:

The result returned by one of the tasks.

Throws:

InterruptedException - if interrupted while waiting

ExecutionException - if no task successfully completes

invokeAny

public <T> T invokeAny(Collection<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.

Specified by:

invokeAny in interface ExecutorService

Overrides:

invokeAny in class AbstractExecutorService

Parameters:

tasks - the collection of tasks

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

The result returned by one of the tasks.

Throws:

InterruptedException - if interrupted while waiting

ExecutionException - if no task successfully completes

TimeoutException - if the given timeout elapses before any task successfully completes