org.xnio
Class IoUtils

java.lang.Object
  org.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 Cancellable	closingCancellable(Closeable c) A cancellable which closes the given resource on cancel.
static IoFuture.Notifier<Closeable,Void>	closingNotifier() Get a notifier that closes the result.
static Executor	directExecutor() Get the direct executor.
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 Random	getThreadLocalRandom() Get a thread-local RNG.
static Cancellable	nullCancellable() Get the null cancellable.
static Closeable	nullCloseable() Get the null closeable.
static Executor	nullExecutor() Get the null executor.
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.
static void	safeShutdownReads(SuspendableReadChannel channel) Safely shutdown reads on the given channel.
static long	transfer(ReadableByteChannel source, long count, ByteBuffer throughBuffer, WritableByteChannel sink) Platform-independent channel-to-channel transfer method.

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

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

safeShutdownReads

public static void safeShutdownReads(SuspendableReadChannel channel)

Safely shutdown reads on the given channel.

Parameters:

channel - the channel

transfer

public static long transfer(ReadableByteChannel source,
                            long count,
                            ByteBuffer throughBuffer,
                            WritableByteChannel sink)
                     throws IOException

Platform-independent channel-to-channel transfer method. Uses regular read and write operations to move bytes from the source channel to the sink channel. After this call, the throughBuffer should be checked for remaining bytes; if there are any, they should be written to the sink channel before proceeding. This method may be used with NIO channels, XNIO channels, or a combination of the two.

If either or both of the given channels are blocking channels, then this method may block.

Parameters:

source - the source channel to read bytes from

count - the number of bytes to transfer (must be >= 0L)

throughBuffer - the buffer to transfer through (must not be null)

sink - the sink channel to write bytes to

Returns:

the number of bytes actually transferred (possibly 0)

Throws:

IOException - if an I/O error occurs during the transfer of bytes

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

getThreadLocalRandom

public static Random getThreadLocalRandom()

Get a thread-local RNG. Do not share this instance with other threads.

Returns:

the thread-local RNG