Class AbstractExecutorService
- java.lang.Object
-
- java.util.concurrent.AbstractExecutorService
- All Implemented Interfaces:
-
Executor
,ExecutorService
- Direct Known Subclasses:
-
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. }
- Since:
- 1.5
Constructor Summary
Constructor | Description |
---|---|
AbstractExecutorService() |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
protected <T> RunnableFuture<T> | newTaskFor(Runnable runnable,
T value) | Returns a |
protected <T> RunnableFuture<T> | newTaskFor(Callable<T> callable) | Returns a |
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. |
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods declared in interface java.util.concurrent.Executor
execute
Methods declared in interface java.util.concurrent.ExecutorService
awaitTermination, invokeAll, invokeAll, invokeAny, invokeAny, isShutdown, isTerminated, shutdown, shutdownNow
Constructor Detail
AbstractExecutorService
public AbstractExecutorService()
Method Detail
newTaskFor
protected <T> RunnableFuture<T> newTaskFor(Runnable runnable, T value)
Returns a RunnableFuture
for the given runnable and default value.
- Type Parameters:
-
T
- the type of the given 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 aFuture
, will yield the given value as its result and provide for cancellation of the underlying task - Since:
- 1.6
newTaskFor
protected <T> RunnableFuture<T> newTaskFor(Callable<T> callable)
Returns a RunnableFuture
for the given callable task.
- Type Parameters:
-
T
- the type of the callable's result - Parameters:
-
callable
- the callable task being wrapped - Returns:
- a
RunnableFuture
which, when run, will call the underlying callable and which, as aFuture
, 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
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
in interfaceExecutorService
- Parameters:
-
task
- the task to submit - Returns:
- a Future representing pending completion of the task
- Throws:
-
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)
Description copied from interface: 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.
- Specified by:
-
submit
in interfaceExecutorService
- Type Parameters:
-
T
- the type of the result - Parameters:
-
task
- the task to submit -
result
- the result to return - Returns:
- a Future representing pending completion of the task
- Throws:
-
RejectedExecutionException
- if the task cannot be scheduled for execution -
NullPointerException
- if the task is null
submit
public <T> Future<T> submit(Callable<T> task)
Description copied from interface: 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.
- Specified by:
-
submit
in interfaceExecutorService
- Type Parameters:
-
T
- the type of the task's result - Parameters:
-
task
- the task to submit - Returns:
- a Future representing pending completion of the task
- Throws:
-
RejectedExecutionException
- if the task cannot be scheduled for execution -
NullPointerException
- if the task is null