Class Future<V>
java.lang.Object
com.mirth.connect.server.userutil.Future<V>
- All Implemented Interfaces:
Future<V>
A
Future represents the result of an asynchronous computation. Methods are provided to
check if the computation is complete, to wait for its completion, and to retrieve the result of
the computation. The result can only be retrieved using method get when the computation
has completed, blocking if necessary until it is ready. Cancellation is performed by the
cancel method. Additional methods are provided to determine if the task completed
normally or was cancelled. Once a computation has completed, the computation cannot be cancelled.
If you would like to use a Future for the sake of cancellability but not provide a usable
result, you can declare types of the form Future<?> and return null as a result
of the underlying task.-
Method Summary
Modifier and TypeMethodDescriptionbooleancancel(boolean mayInterruptIfRunning) Attempts to cancel execution of this task.get()Waits if necessary for the computation to complete, and then retrieves its result.get(long timeoutInMillis) Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.booleanReturnstrueif this task was cancelled before it completed normally.booleanisDone()Returnstrueif this task completed.
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Method Details
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cancel
public boolean cancel(boolean mayInterruptIfRunning) Attempts to cancel execution of this task. This attempt will fail if the task has already completed, has already been cancelled, or could not be cancelled for some other reason. If successful, and this task has not started whencancelis called, this task should never run. If the task has already started, then themayInterruptIfRunningparameter determines whether the thread executing this task should be interrupted in an attempt to stop the task. After this method returns, subsequent calls toisDone()will always returntrue. Subsequent calls toisCancelled()will always returntrueif this method returnedtrue.- Specified by:
cancelin interfaceFuture<V>- Parameters:
mayInterruptIfRunning-trueif the thread executing this task should be interrupted; otherwise, in-progress tasks are allowed to complete- Returns:
falseif the task could not be cancelled, typically because it has already completed normally;trueotherwise
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isCancelled
public boolean isCancelled()Returnstrueif this task was cancelled before it completed normally.- Specified by:
isCancelledin interfaceFuture<V>- Returns:
trueif this task was cancelled before it completed
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isDone
public boolean isDone()Returnstrueif this task completed. Completion may be due to normal termination, an exception, or cancellation -- in all of these cases, this method will returntrue. -
get
Waits if necessary for the computation to complete, and then retrieves its result.- Specified by:
getin interfaceFuture<V>- Returns:
- the computed result
- Throws:
CancellationException- if the computation was cancelledExecutionException- if the computation threw an exceptionInterruptedException- if the current thread was interrupted while waiting
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get
public V get(long timeoutInMillis) throws InterruptedException, ExecutionException, TimeoutException Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.- Parameters:
timeoutInMillis- the maximum time to wait, in milliseconds- Returns:
- the computed result
- Throws:
CancellationException- if the computation was cancelledExecutionException- if the computation threw an exceptionInterruptedException- if the current thread was interrupted while waitingTimeoutException- if the wait timed out- See Also:
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get
public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException Waits if necessary for at most the given time for the computation to complete, and then retrieves its result, if available.- Specified by:
getin interfaceFuture<V>- Parameters:
timeout- the maximum time to waitunit- the time unit of the timeout argument- Returns:
- the computed result
- Throws:
CancellationException- if the computation was cancelledExecutionException- if the computation threw an exceptionInterruptedException- if the current thread was interrupted while waitingTimeoutException- if the wait timed out
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