AbstractExecutorService (Java Platform SE 6) (original) (raw)
java.util.concurrent
Class AbstractExecutorService
java.lang.Object
java.util.concurrent.AbstractExecutorService
All Implemented Interfaces:
Direct Known Subclasses:
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 aRunnableFuture 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 thanFutureTask.
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 implements RunnableFuture {...}
protected RunnableFuture newTaskFor(Callable c) { return new CustomTask(c); } protected RunnableFuture newTaskFor(Runnable r, V v) { return new CustomTask(r, v); } // ... add constructors, etc. }
Since:
1.5
| Constructor Summary |
|---|
| AbstractExecutorService() |
| Method Summary | |
|---|---|
| List<Future> | invokeAll(Collection<? extends Callable> tasks) Executes the given tasks, returning a list of Futures holding their status and results when all complete. |
| List<Future> | [invokeAll](../../../java/util/concurrent/AbstractExecutorService.html#invokeAll%28java.util.Collection, long, java.util.concurrent.TimeUnit%29)(Collection<? extends Callable> 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. |
| T | invokeAny(Collection<? extends Callable> tasks) Executes the given tasks, returning the result of one that has completed successfully (i.e., without throwing an exception), if any do. |
| T | [invokeAny](../../../java/util/concurrent/AbstractExecutorService.html#invokeAny%28java.util.Collection, long, java.util.concurrent.TimeUnit%29)(Collection<? extends Callable> 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 RunnableFuture | newTaskFor(Callable callable) Returns a RunnableFuture for the given callable task. |
| protected RunnableFuture | [newTaskFor](../../../java/util/concurrent/AbstractExecutorService.html#newTaskFor%28java.lang.Runnable, T%29)(Runnable runnable, T value) Returns a RunnableFuture for the given runnable and default value. |
| Future | submit(Callable 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. |
| Future | [submit](../../../java/util/concurrent/AbstractExecutorService.html#submit%28java.lang.Runnable, T%29)(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](../../../java/lang/Object.html#wait%28long, int%29) |
| Methods inherited from interface java.util.concurrent.ExecutorService |
|---|
| [awaitTermination](../../../java/util/concurrent/ExecutorService.html#awaitTermination%28long, java.util.concurrent.TimeUnit%29), isShutdown, isTerminated, shutdown, shutdownNow |
| Methods inherited from interface java.util.concurrent.Executor |
|---|
| execute |
| Constructor Detail |
|---|
AbstractExecutorService
public AbstractExecutorService()
| Method Detail |
|---|
newTaskFor
protected RunnableFuture newTaskFor(Runnable runnable, T value)
Returns a RunnableFuture for the given runnable and default value.
Parameters:
runnable - the runnable task being wrapped
value - the default value for the returned future
Returns:
a RunnableFuture 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 task.
Since:
1.6
newTaskFor
protected RunnableFuture newTaskFor(Callable callable)
Returns a RunnableFuture for the given callable task.
Parameters:
callable - the callable task being wrapped
Returns:
a RunnableFuture 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 task.
Since:
1.6
submit
public Future<?> submit(Runnable task)
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#submit%28java.lang.Runnable%29)
Submits a Runnable task for execution and returns a Future representing that task. The Future's get method will return null upon successful completion.
Specified by:
[submit](../../../java/util/concurrent/ExecutorService.html#submit%28java.lang.Runnable%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
Parameters:
task - the task to submit
Returns:
a Future representing pending completion of the task
submit
public Future submit(Runnable task, T result)
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#submit%28java.lang.Runnable, T%29)
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.
Specified by:
[submit](../../../java/util/concurrent/ExecutorService.html#submit%28java.lang.Runnable, T%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
Parameters:
task - the task to submit
result - the result to return
Returns:
a Future representing pending completion of the task
submit
public Future submit(Callable task)
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#submit%28java.util.concurrent.Callable%29)
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 formresult = 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 toCallable form so they can be submitted.
Specified by:
[submit](../../../java/util/concurrent/ExecutorService.html#submit%28java.util.concurrent.Callable%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
Parameters:
task - the task to submit
Returns:
a Future representing pending completion of the task
invokeAny
public T invokeAny(Collection<? extends Callable> tasks) throws InterruptedException, ExecutionException
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#invokeAny%28java.util.Collection%29)
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](../../../java/util/concurrent/ExecutorService.html#invokeAny%28java.util.Collection%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
Parameters:
tasks - the collection of tasks
Returns:
the result returned by one of the tasks
Throws:
[InterruptedException](../../../java/lang/InterruptedException.html "class in java.lang") - if interrupted while waiting
[ExecutionException](../../../java/util/concurrent/ExecutionException.html "class in java.util.concurrent") - if no task successfully completes
invokeAny
public T invokeAny(Collection<? extends Callable> tasks, long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#invokeAny%28java.util.Collection, long, java.util.concurrent.TimeUnit%29)
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](../../../java/util/concurrent/ExecutorService.html#invokeAny%28java.util.Collection, long, java.util.concurrent.TimeUnit%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
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](../../../java/lang/InterruptedException.html "class in java.lang") - if interrupted while waiting
[ExecutionException](../../../java/util/concurrent/ExecutionException.html "class in java.util.concurrent") - if no task successfully completes
[TimeoutException](../../../java/util/concurrent/TimeoutException.html "class in java.util.concurrent") - if the given timeout elapses before any task successfully completes
invokeAll
public List<Future> invokeAll(Collection<? extends Callable> tasks) throws InterruptedException
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#invokeAll%28java.util.Collection%29)
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.
Specified by:
[invokeAll](../../../java/util/concurrent/ExecutorService.html#invokeAll%28java.util.Collection%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
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](../../../java/lang/InterruptedException.html "class in java.lang") - if interrupted while waiting, in which case unfinished tasks are cancelled.
invokeAll
public List<Future> invokeAll(Collection<? extends Callable> tasks, long timeout, TimeUnit unit) throws InterruptedException
Description copied from interface: [ExecutorService](../../../java/util/concurrent/ExecutorService.html#invokeAll%28java.util.Collection, long, java.util.concurrent.TimeUnit%29)
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.
Specified by:
[invokeAll](../../../java/util/concurrent/ExecutorService.html#invokeAll%28java.util.Collection, long, java.util.concurrent.TimeUnit%29) in interface [ExecutorService](../../../java/util/concurrent/ExecutorService.html "interface in java.util.concurrent")
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 these tasks will not have completed.
Throws:
[InterruptedException](../../../java/lang/InterruptedException.html "class in java.lang") - if interrupted while waiting, in which case unfinished tasks are cancelled
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