| java.util.concurrent.CompletionService
| CompletionService | | public interface CompletionService (Code) | | A service that decouples the production of new asynchronous tasks
from the consumption of the results of completed tasks. Producers
submit tasks for execution. Consumers take
completed tasks and process their results in the order they
complete. A CompletionService can for example be used to
manage asynchronous IO, in which tasks that perform reads are
submitted in one part of a program or system, and then acted upon
in a different part of the program when the reads complete,
possibly in a different order than they were requested.
Typically, a CompletionService relies on a separate
Executor to actually execute the tasks, in which case the
CompletionService only manages an internal completion
queue. The
ExecutorCompletionService class provides an
implementation of this approach.
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| Method Summary | |
| Future<V> | poll()
Retrieves and removes the Future representing the next
completed task or null if none are present. | | Future<V> | poll(long timeout, TimeUnit unit)
Retrieves and removes the Future representing the next
completed task, waiting if necessary up to the specified wait
time if none are yet present. | | Future<V> | submit(Callable<V> task)
Submits a value-returning task for execution and returns a Future
representing the pending results of the task. | | Future<V> | submit(Runnable task, V result)
Submits a Runnable task for execution and returns a Future
representing that task. | | Future<V> | take()
Retrieves and removes the Future representing the next
completed task, waiting if none are yet present. |
| poll | | Future<V> poll()(Code) | | Retrieves and removes the Future representing the next
completed task or null if none are present.
the Future representing the next completed task, ornull if none are present. |
| poll | | Future<V> poll(long timeout, TimeUnit unit) throws InterruptedException(Code) | | Retrieves and removes the Future representing the next
completed task, waiting if necessary up to the specified wait
time if none are yet present.
Parameters:
timeout - how long to wait before giving up, in units ofunit
Parameters:
unit - a TimeUnit determining how to interpret thetimeout parameter the Future representing the next completed task ornull if the specified waiting time elapses before oneis present.
throws:
InterruptedException - if interrupted while waiting. |
| submit | | Future<V> submit(Callable<V> task)(Code) | | Submits a value-returning task for execution and returns a Future
representing the pending results of the task. Upon completion,
this task may be taken or polled.
Parameters:
task - the task to submit a Future representing pending completion of the task
throws:
RejectedExecutionException - if task cannot be scheduledfor execution
throws:
NullPointerException - if task null |
| submit | | Future<V> submit(Runnable task, V result)(Code) | | Submits a Runnable task for execution and returns a Future
representing that task. Upon completion,
this task may be taken or polled.
Parameters:
task - the task to submit
Parameters:
result - the result to return upon successful completion a Future representing pending completion of the task,and whose get() method will return the given result value upon completion
throws:
RejectedExecutionException - if task cannot be scheduledfor execution
throws:
NullPointerException - if task null |
| take | | Future<V> take() throws InterruptedException(Code) | | Retrieves and removes the Future representing the next
completed task, waiting if none are yet present.
the Future representing the next completed task
throws:
InterruptedException - if interrupted while waiting. |
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