Package gov.usgs.util

Class FutureExecutorTask<T>

java.lang.Object

gov.usgs.util.ExecutorTask<T>

gov.usgs.util.FutureExecutorTask<T>

All Implemented Interfaces:

Runnable, Future<T>

public class FutureExecutorTask<T>
extends ExecutorTask<T>

FutureExecutorTask overrides how timeouts are handled to use a separate executor service with Futures.

Field Summary

Fields

Modifier and Type	Field	Description
protected ExecutorService	backgroundService	ExecutorService used to execute callable.
static final int	DEFAULT_NUM_TRIES	Default number of tries to run this task.
static final long	DEFAULT_RETRY_DELAY	Default number of milliseconds to wait before a retry.
static final long	DEFAULT_TIMEOUT	Default timeout for this task.

Fields inherited from class gov.usgs.util.ExecutorTask

callable, cancelled, done, maxTries, name, numTries, result, retryDelay, retryTimer, runThread, service, syncObject, timeout

Constructor Summary

Constructors

Constructor	Description
FutureExecutorTask(ExecutorService backgroundService, ExecutorService service, int maxTries, long timeout, Runnable runnable, T result)	Wraps a runnable and result using the CallableRunnable class.
FutureExecutorTask(ExecutorService backgroundService, ExecutorService service, int maxTries, long timeout, Callable<T> callable)	Construct a new ExecutorTask
FutureExecutorTask(ExecutorService backgroundService, ExecutorService service, int maxTries, long timeout, Callable<T> callable, Timer retryTimer, long retryDelay)	Construct a new FutureExecutorTask

Method Summary

Modifier and Type	Method	Description
void	run()	Run calls the callable, scheduling timeout interruption, catching exceptions, and potentially resubmitting to the executor service.

Methods inherited from class gov.usgs.util.ExecutorTask

cancel, get, get, getCallable, getExceptions, getMaxTries, getName, getNumTries, getRetryDelay, getRetryTimer, isCancelled, isDone, setDone, setName, setRetryDelay, setRetryTimer

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_RETRY_DELAY

public static final long DEFAULT_RETRY_DELAY

Default number of milliseconds to wait before a retry.

See Also:

• Constant Field Values

DEFAULT_NUM_TRIES

public static final int DEFAULT_NUM_TRIES

Default number of tries to run this task.

See Also:

• Constant Field Values

DEFAULT_TIMEOUT

public static final long DEFAULT_TIMEOUT

Default timeout for this task.

See Also:

• Constant Field Values

backgroundService

protected ExecutorService backgroundService

ExecutorService used to execute callable.

Constructor Details

FutureExecutorTask

public FutureExecutorTask(ExecutorService backgroundService,
 ExecutorService service,
 int maxTries,
 long timeout,
 Callable<T> callable)

Construct a new ExecutorTask

Parameters:

backgroundService - ExecutorService used to execute callable.

service - ExecutorService that this task will be submitted to.

maxTries - maximum number of tries callable can throw an exception or timeout before giving up. < 1 means never run.

timeout - number of milliseconds to allow callable to run before it is interrupted. <= 0 means never timeout.

callable - the callable to call. To work well, the callable should handle interrupts gracefully.

See Also:

• InterruptedException

FutureExecutorTask

public FutureExecutorTask(ExecutorService backgroundService,
 ExecutorService service,
 int maxTries,
 long timeout,
 Runnable runnable,
 T result)

Wraps a runnable and result using the CallableRunnable class.

Parameters:

backgroundService - ExecutorService used to execute callable

service - ExecutorService that this task will be submitted to.

maxTries - maximum number of tries callable can throw an exception or timeout before giving up. < 1 means never run.

timeout - number of milliseconds to allow callable to run before it is interrupted. <= 0 means never timeout.

runnable - a runnable

result - the result passed to Executors callable

See Also:

• Executors.callable(Runnable, Object)

FutureExecutorTask

public FutureExecutorTask(ExecutorService backgroundService,
 ExecutorService service,
 int maxTries,
 long timeout,
 Callable<T> callable,
 Timer retryTimer,
 long retryDelay)

Construct a new FutureExecutorTask

Parameters:

backgroundService - ExecutorService used to execute callable

service - ExecutorService that this task will be submitted to.

maxTries - maximum number of tries callable can throw an exception or timeout before giving up. < 1 means never run.

timeout - number of milliseconds to allow callable to run before it is interrupted. <= 0 means never timeout.

callable - the callable to call. To work well, the callable should handle interrupts gracefully.

retryTimer - a timer used to schedule retries when retryDelay is non-zero.

retryDelay - the number of milliseconds to wait before retrying after an exception.

See Also:

• on interrupted

Method Details

run

public void run()

Run calls the callable, scheduling timeout interruption, catching exceptions, and potentially resubmitting to the executor service.

Specified by:

run in interface Runnable

Overrides:

run in class ExecutorTask<T>