程序包 java.util.concurrent

类 AbstractExecutorService

java.lang.Object

java.util.concurrent.AbstractExecutorService

所有已实现的接口:

Executor, ExecutorService

直接已知子类:

ForkJoinPool, ThreadPoolExecutor

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.
 }

从以下版本开始:

1.5

构造器概要

构造器

构造器	说明
AbstractExecutorService()

方法概要

限定符和类型	方法	说明
<T> List<Future<T>>	invokeAll(Collection<? extends Callable<T>> tasks)	Executes the given tasks, returning a list of Futures holding their status and results when all complete.
<T> List<Future<T>>	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.
<T> T	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.
<T> T	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 <T> RunnableFuture<T>	newTaskFor(Runnable runnable, T value)	Returns a RunnableFuture for the given runnable and default value.
protected <T> RunnableFuture<T>	newTaskFor(Callable<T> callable)	Returns a RunnableFuture for the given callable 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.
<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.

从接口继承的方法 java.util.concurrent.Executor

execute

从接口继承的方法 java.util.concurrent.ExecutorService

awaitTermination, isShutdown, isTerminated, shutdown, shutdownNow

从类继承的方法 java.lang.Object

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

构造器详细资料

AbstractExecutorService

public AbstractExecutorService()

方法详细资料

newTaskFor

protected <T> RunnableFuture<T> newTaskFor(Runnable runnable,
                                           T value)

Returns a RunnableFuture for the given runnable and default value.

类型参数:

T - the type of the given value

参数:

runnable - the runnable task being wrapped

value - the default value for the returned future

返回:

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

从以下版本开始:

1.6

newTaskFor

protected <T> RunnableFuture<T> newTaskFor(Callable<T> callable)

Returns a RunnableFuture for the given callable task.

类型参数:

T - the type of the callable's result

参数:

callable - the callable task being wrapped

返回:

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

从以下版本开始:

1.6

submit

public Future<?> submit(Runnable task)

从接口复制的说明: 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.

指定者:

submit 在接口中 ExecutorService

参数:

task - the task to submit

返回:

a Future representing pending completion of the task

抛出:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if the task is null

submit

public <T> Future<T> submit(Runnable task,
                            T result)

从接口复制的说明: 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.

指定者:

submit 在接口中 ExecutorService

类型参数:

T - the type of the result

参数:

task - the task to submit

result - the result to return

返回:

a Future representing pending completion of the task

抛出:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if the task is null

submit

public <T> Future<T> submit(Callable<T> task)

从接口复制的说明: 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.

指定者:

submit 在接口中 ExecutorService

类型参数:

T - the type of the task's result

参数:

task - the task to submit

返回:

a Future representing pending completion of the task

抛出:

RejectedExecutionException - if the task cannot be scheduled for execution

NullPointerException - if the task is null

invokeAny

public <T> T invokeAny(Collection<? extends Callable<T>> tasks)
                throws ExecutionException,
                       InterruptedException

从接口复制的说明: 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.

指定者:

invokeAny 在接口中 ExecutorService

类型参数:

T - the type of the values returned from the tasks

参数:

tasks - the collection of tasks

返回:

the result returned by one of the tasks

抛出:

ExecutionException - if no task successfully completes

InterruptedException - if interrupted while waiting

invokeAny

public <T> T invokeAny(Collection<? extends Callable<T>> tasks,
                       long timeout,
                       TimeUnit unit)
                throws ExecutionException,
                       InterruptedException,
                       TimeoutException

从接口复制的说明: 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.

指定者:

invokeAny 在接口中 ExecutorService

类型参数:

T - the type of the values returned from the tasks

参数:

tasks - the collection of tasks

timeout - the maximum time to wait

unit - the time unit of the timeout argument

返回:

the result returned by one of the tasks

抛出:

ExecutionException - if no task successfully completes

InterruptedException - if interrupted while waiting

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

invokeAll

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

从接口复制的说明: 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.

指定者:

invokeAll 在接口中 ExecutorService

类型参数:

T - the type of the values returned from the tasks

参数:

tasks - the collection of tasks

返回:

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

抛出:

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

invokeAll

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

从接口复制的说明: 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.

指定者:

invokeAll 在接口中 ExecutorService

类型参数:

T - the type of the values returned from the tasks

参数:

tasks - the collection of tasks

timeout - the maximum time to wait

unit - the time unit of the timeout argument

返回:

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.

抛出:

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