public abstract class AbstractExecutorService extends Objectimplements ExecutorService
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 and Description |
|---|
AbstractExecutorService()
|
| Modifier and Type | Method and Description |
|---|---|
<T> List |
invokeAll(Collection
Executes the given tasks, returning a list of Futures holding their status and results when all complete.
|
<T> List |
invokeAll(Collection
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
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
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 |
newTaskFor(Callable
Returns a
RunnableFuture for the given callable task.
|
protected <T> RunnableFuture |
newTaskFor(Runnable
Returns a
RunnableFuture for the given runnable and default value.
|
<T> Future |
submit(Callable
Submits a value-returning task for execution and returns a Future representing the pending results of the task.
|
Future |
submit(Runnable
Submits a Runnable task for execution and returns a Future representing that task.
|
<T> Future |
submit(Runnable
Submits a Runnable task for execution and returns a Future representing that task.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitawaitTermination, isShutdown, isTerminated, shutdown, shutdownNowprotected <T> RunnableFuture<T> newTaskFor(Runnable runnable, T value)
RunnableFuture for the given runnable and default value.
T - the type of the given value
runnable - the runnable task being wrapped
value - the default value for the returned future
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
protected <T> RunnableFuture<T> newTaskFor(Callable <T> callable)
RunnableFuture for the given callable task.
T - the type of the callable's result
callable - the callable task being wrapped
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
public Future<?> submit(Runnable task)
ExecutorService
get method will return
null upon
successful completion.
submit in interface
ExecutorService
task - the task to submit
RejectedExecutionException - if the task cannot be scheduled for execution
NullPointerException - if the task is null
public <T> Future<T> submit(Runnable task, T result)
ExecutorService
get method will return the given result upon successful completion.
submit in interface
ExecutorService
T - the type of the result
task - the task to submit
result - the result to return
RejectedExecutionException - if the task cannot be scheduled for execution
NullPointerException - if the task is null
public <T> Future<T> submit(Callable <T> task)
ExecutorService
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.
submit in interface
ExecutorService
T - the type of the task's result
task - the task to submit
RejectedExecutionException - if the task cannot be scheduled for execution
NullPointerException - if the task is null
public <T> T invokeAny(Collection<? extends Callable <T>> tasks) throws InterruptedException , ExecutionException
ExecutorService
invokeAny in interface
ExecutorService
T - the type of the values returned from the tasks
tasks - the collection of tasks
InterruptedException - if interrupted while waiting
ExecutionException - if no task successfully completes
public <T> T invokeAny(Collection<? extends Callable <T>> tasks, long timeout, TimeUnit unit) throws InterruptedException , ExecutionException , TimeoutException
ExecutorService
invokeAny in interface
ExecutorService
T - the type of the values returned from the tasks
tasks - the collection of tasks
timeout - the maximum time to wait
unit - 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 completes
public <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
T - the type of the values returned from the tasks
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
T - the type of the values returned from the tasks
tasks - the collection of tasks
timeout - the maximum time to wait
unit - the time unit of the timeout argument
InterruptedException - if interrupted while waiting, in which case unfinished tasks are cancelled