|
Java™ Platform Standard Ed. 6 |
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object java.util.concurrent.AbstractExecutorService
public abstract class AbstractExecutorService
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. }
Constructor Summary | |
---|---|
AbstractExecutorService()
|
Method Summary | ||
---|---|---|
|
invokeAll(Collection<? extends Callable<T>> tasks)
Executes the given tasks, returning a list of Futures holding their status and results when all complete. |
|
|
invokeAll(Collection<? extends Callable<T>> tasks,
long timeout,
TimeUnit unit)
Executes the given tasks, returning a list of Futures holding their status and results when all complete or the timeout expires, whichever happens first. |
|
|
invokeAny(Collection<? extends 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. |
|
|
invokeAny(Collection<? extends 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. |
|
protected
|
newTaskFor(Callable<T> callable)
Returns a RunnableFuture for the given callable task. |
|
protected
|
newTaskFor(Runnable runnable,
T value)
Returns a RunnableFuture for the given runnable and default value. |
|
|
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. |
|
|
submit(Runnable task,
T result)
Submits a Runnable task for execution and returns a Future representing that task. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface java.util.concurrent.ExecutorService |
---|
awaitTermination, isShutdown, isTerminated, shutdown, shutdownNow |
Methods inherited from interface java.util.concurrent.Executor |
---|
execute |
Constructor Detail |
---|
public AbstractExecutorService()
Method Detail |
---|
protected <T> RunnableFuture<T> newTaskFor(Runnable runnable, T value)
runnable
- the runnable task being wrappedvalue
- the default value for the returned future
protected <T> RunnableFuture<T> newTaskFor(Callable<T> callable)
callable
- the callable task being wrapped
public Future<?> submit(Runnable task)
ExecutorService
submit
in interface ExecutorService
task
- the task to submit
public <T> Future<T> submit(Runnable task, T result)
ExecutorService
submit
in interface ExecutorService
task
- the task to submitresult
- the result to return
public <T> Future<T> submit(Callable<T> task)
ExecutorService
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
task
- the task to submit
public <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException
ExecutorService
invokeAny
in interface ExecutorService
tasks
- the collection of tasks
InterruptedException
- if interrupted while waiting
ExecutionException
- if no task successfully completespublic <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException
ExecutorService
invokeAny
in interface ExecutorService
tasks
- the collection of taskstimeout
- the maximum time to waitunit
- the time unit of the timeout argument
InterruptedException
- if interrupted while waiting
ExecutionException
- if no task successfully completes
TimeoutException
- if the given timeout elapses before
any task successfully completespublic <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks) throws InterruptedException
ExecutorService
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
tasks
- the collection of tasks
InterruptedException
- if interrupted while waiting, in
which case unfinished tasks are cancelled.public <T> List<Future<T>> invokeAll(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException
ExecutorService
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
tasks
- the collection of taskstimeout
- the maximum time to waitunit
- the time unit of the timeout argument
InterruptedException
- if interrupted while waiting, in
which case unfinished tasks are cancelled
|
Java™ Platform Standard Ed. 6 |
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
Copyright © 1993, 2010, Oracle and/or its affiliates. All rights reserved.