org.jboss.xnio
Class IoUtils

java.lang.Object
  org.jboss.xnio.IoUtils

public final class IoUtils
extends Object

General I/O utility methods.

Method Summary

static IoFuture.Notifier<Object,Closeable>	attachmentClosingNotifier() Get a notifier that closes the attachment.
static void	awaitAll(IoFuture<?>... futures) Wait for all the futures to complete.
static void	awaitAllInterruptibly(IoFuture<?>... futures) Wait for all the futures to complete.
static <I,O> IoFuture<? extends O>	cast(IoFuture<I> parent, Class<O> type) Create an IoFuture which wraps another IoFuture, but returns a different type.
static <T extends Channel> IoFuture.Notifier<T,ChannelListener<? super T>>	channelListenerNotifier() Get the notifier that invokes the channel listener given as an attachment.
static CloseableExecutor	closeableExecutor(ExecutorService executorService, long timeout, TimeUnit unit) Get a closeable executor wrapper for an ExecutorService.
static Cancellable	closingCancellable(Closeable c) A cancellable which closes the given resource on cancel.
static ChannelListener<Channel>	closingChannelListener() Get a channel listener which closes the channel when notified.
static IoFuture.Notifier<Closeable,Void>	closingNotifier() Get a notifier that closes the result.
static Executor	directExecutor() Get the direct executor.
static <T extends Channel> ChannelListener<T>	executorChannelListener(ChannelListener<T> listener, Executor executor) Get a channel listener which executes a delegate channel listener via an executor.
static <T extends Channel> Runnable	getChannelListenerTask(T channel, ChannelListener<? super T> channelListener) Get a task which invokes the given channel listener on the given channel.
static <T extends Channel> ChannelListener.Setter<T>	getDelegatingSetter(ChannelListener.Setter<? extends Channel> target, T realChannel) Get a channel listener setter which delegates to the given target setter with a different channel type.
static <T> Future<T>	getFuture(IoFuture<T> ioFuture) Get a java.util.concurrent-style Future instance wrapper for an IoFuture instance.
static <T> IoFuture.Notifier<T,FutureResult<T>>	getManagerNotifier() Get a notifier which forwards the result to another IoFuture's manager.
static <T extends Channel> ChannelSource<T>	getRetryingChannelSource(ChannelSource<T> delegate, int maxTries) A channel source which tries to acquire a channel from a delegate channel source the given number of times before giving up.
static <T extends Channel> ChannelListener.Setter<T>	getSetter(AtomicReference<ChannelListener<? super T>> atomicReference) Get a setter based on an atomic reference.
static <T extends Channel,C> ChannelListener.Setter<T>	getSetter(C channel, AtomicReferenceFieldUpdater<C,ChannelListener> updater) Get a setter based on an atomic reference field updater.
static <T extends Channel> void	invokeChannelListener(Executor executor, T channel, ChannelListener<? super T> channelListener) Invoke a channel listener on a given channel, logging any errors, using the given executor.
static <T extends Channel> boolean	invokeChannelListener(T channel, ChannelListener<? super T> channelListener) Invoke a channel listener on a given channel, logging any errors.
static Cancellable	nullCancellable() Get the null cancellable.
static ChannelListener<Channel>	nullChannelListener() Get a channel listener which does nothing.
static Closeable	nullCloseable() Get the null closeable.
static Executor	nullExecutor() Get the null executor.
static <T extends Channel> ChannelListener.Setter<T>	nullSetter() Get a channel listener setter which does nothing.
static <T> IoFuture.Notifier<T,Result<T>>	resultNotifier() Get the result notifier.
static <T> IoFuture.Notifier<T,Void>	runnableNotifier(Runnable runnable) Get a notifier that runs the supplied action.
static void	safeClose(Closeable resource) Close a resource, logging an error if an error occurs.
static void	safeClose(DatagramSocket resource) Close a resource, logging an error if an error occurs.
static void	safeClose(Handler resource) Close a resource, logging an error if an error occurs.
static void	safeClose(IoFuture<? extends Closeable> futureResource) Close a future resource, logging an error if an error occurs.
static void	safeClose(Selector resource) Close a resource, logging an error if an error occurs.
static void	safeClose(ServerSocket resource) Close a resource, logging an error if an error occurs.
static void	safeClose(Socket resource) Close a resource, logging an error if an error occurs.
static void	safeClose(ZipFile resource) Close a resource, logging an error if an error occurs.

Methods inherited from class java.lang.Object

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

Method Detail

directExecutor

public static Executor directExecutor()

Get the direct executor. This is an executor that executes the provided task in the same thread.

Returns:

a direct executor

nullExecutor

public static Executor nullExecutor()

Get the null executor. This is an executor that never actually executes the provided task.

Returns:

a null executor

closeableExecutor

public static CloseableExecutor closeableExecutor(ExecutorService executorService,
                                                  long timeout,
                                                  TimeUnit unit)

Get a closeable executor wrapper for an ExecutorService. The given timeout is used to determine how long the close() method will wait for a clean shutdown before the executor is shut down forcefully.

Parameters:

executorService - the executor service

timeout - the timeout

unit - the unit for the timeout

Returns:

a new closeable executor

nullCloseable

public static Closeable nullCloseable()

Get the null closeable. This is a simple Closeable instance that does nothing when its close() method is invoked.

Returns:

the null closeable

safeClose

public static void safeClose(Closeable resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(Socket resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(DatagramSocket resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(Selector resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(ServerSocket resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(ZipFile resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(Handler resource)

Close a resource, logging an error if an error occurs.

Parameters:

resource - the resource to close

safeClose

public static void safeClose(IoFuture<? extends Closeable> futureResource)

Close a future resource, logging an error if an error occurs. Attempts to cancel the operation if it is still in progress.

Parameters:

futureResource - the resource to close

attachmentClosingNotifier

public static IoFuture.Notifier<Object,Closeable> attachmentClosingNotifier()

Get a notifier that closes the attachment.

Returns:

a notifier which will close its attachment

closingNotifier

public static IoFuture.Notifier<Closeable,Void> closingNotifier()

Get a notifier that closes the result.

Returns:

a notifier which will close the result of the operation (if successful)

runnableNotifier

public static <T> IoFuture.Notifier<T,Void> runnableNotifier(Runnable runnable)

Get a notifier that runs the supplied action.

Type Parameters:

T - the future type (not used)

Parameters:

runnable - the notifier type

Returns:

a notifier which will run the given command

resultNotifier

public static <T> IoFuture.Notifier<T,Result<T>> resultNotifier()

Get the result notifier. This notifier will forward the result of the IoFuture to the attached Result.

Type Parameters:

T - the result type

Returns:

the notifier

channelListenerNotifier

public static <T extends Channel> IoFuture.Notifier<T,ChannelListener<? super T>> channelListenerNotifier()

Get the notifier that invokes the channel listener given as an attachment.

Type Parameters:

T - the channel type

Returns:

the notifier

getFuture

public static <T> Future<T> getFuture(IoFuture<T> ioFuture)

Get a java.util.concurrent-style Future instance wrapper for an IoFuture instance.

Parameters:

ioFuture - the IoFuture to wrap

Returns:

a Future

awaitAll

public static void awaitAll(IoFuture<?>... futures)

Wait for all the futures to complete.

Parameters:

futures - the futures to wait for

awaitAllInterruptibly

public static void awaitAllInterruptibly(IoFuture<?>... futures)
                                  throws InterruptedException

Wait for all the futures to complete.

Parameters:

futures - the futures to wait for

Throws:

InterruptedException - if the current thread is interrupted while waiting

cast

public static <I,O> IoFuture<? extends O> cast(IoFuture<I> parent,
                                               Class<O> type)

Create an IoFuture which wraps another IoFuture, but returns a different type.

Type Parameters:

I - the type of the original result

O - the type of the wrapped result

Parameters:

parent - the original IoFuture

type - the class of the new IoFuture

Returns:

a wrapper IoFuture

invokeChannelListener

public static <T extends Channel> boolean invokeChannelListener(T channel,
                                                                ChannelListener<? super T> channelListener)

Invoke a channel listener on a given channel, logging any errors.

Type Parameters:

T - the channel type

Parameters:

channel - the channel

channelListener - the channel listener

Returns:

true if the listener completed successfully, or false if it failed

invokeChannelListener

public static <T extends Channel> void invokeChannelListener(Executor executor,
                                                             T channel,
                                                             ChannelListener<? super T> channelListener)

Invoke a channel listener on a given channel, logging any errors, using the given executor.

Type Parameters:

T - the channel type

Parameters:

executor - the executor

channel - the channel

channelListener - the channel listener

getChannelListenerTask

public static <T extends Channel> Runnable getChannelListenerTask(T channel,
                                                                  ChannelListener<? super T> channelListener)

Get a task which invokes the given channel listener on the given channel.

Type Parameters:

T - the channel type

Parameters:

channel - the channel

channelListener - the channel listener

Returns:

the runnable task

closingChannelListener

public static ChannelListener<Channel> closingChannelListener()

Get a channel listener which closes the channel when notified.

Returns:

the channel listener

nullChannelListener

public static ChannelListener<Channel> nullChannelListener()

Get a channel listener which does nothing.

Returns:

the null channel listener

getSetter

public static <T extends Channel,C> ChannelListener.Setter<T> getSetter(C channel,
                                                                        AtomicReferenceFieldUpdater<C,ChannelListener> updater)

Get a setter based on an atomic reference field updater. Used by channel implementations to avoid having to define an anonymous class for each listener field.

Type Parameters:

T - the channel type

C - the holding class

Parameters:

channel - the channel

updater - the updater

Returns:

the setter

getSetter

public static <T extends Channel> ChannelListener.Setter<T> getSetter(AtomicReference<ChannelListener<? super T>> atomicReference)

Get a setter based on an atomic reference. Used by channel implementations to avoid having to define an anonymous class for each listener field.

Type Parameters:

T - the channel type

Parameters:

atomicReference - the atomic reference

Returns:

the setter

getDelegatingSetter

public static <T extends Channel> ChannelListener.Setter<T> getDelegatingSetter(ChannelListener.Setter<? extends Channel> target,
                                                                                T realChannel)

Get a channel listener setter which delegates to the given target setter with a different channel type.

Type Parameters:

T - the real channel type

Parameters:

target - the target setter

realChannel - the channel to send in to the listener

Returns:

the delegating setter

nullSetter

public static <T extends Channel> ChannelListener.Setter<T> nullSetter()

Get a channel listener setter which does nothing.

Type Parameters:

T - the channel type

Returns:

a setter which does nothing

getManagerNotifier

public static <T> IoFuture.Notifier<T,FutureResult<T>> getManagerNotifier()

Get a notifier which forwards the result to another IoFuture's manager.

Type Parameters:

T - the channel type

Returns:

the notifier

getRetryingChannelSource

public static <T extends Channel> ChannelSource<T> getRetryingChannelSource(ChannelSource<T> delegate,
                                                                            int maxTries)

A channel source which tries to acquire a channel from a delegate channel source the given number of times before giving up.

Type Parameters:

T - the channel type

Parameters:

delegate - the delegate channel source

maxTries - the number of times to retry

Returns:

the retrying channel source

closingCancellable

public static Cancellable closingCancellable(Closeable c)

A cancellable which closes the given resource on cancel.

Parameters:

c - the resource

Returns:

the cancellable

nullCancellable

public static Cancellable nullCancellable()

Get the null cancellable.

Returns:

the null cancellable

executorChannelListener

public static <T extends Channel> ChannelListener<T> executorChannelListener(ChannelListener<T> listener,
                                                                             Executor executor)

Get a channel listener which executes a delegate channel listener via an executor. If an exception occurs submitting the task, the associated channel is closed.

Type Parameters:

T - the channel type

Parameters:

listener - the listener to invoke

executor - the executor with which to invoke the listener

Returns:

a delegating channel listener