java.nio.channels.spi

Class AbstractSelectableChannel

java.lang.Object

java.nio.channels.spi.AbstractInterruptibleChannel

java.nio.channels.SelectableChannel

java.nio.channels.spi.AbstractSelectableChannel

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, InterruptibleChannel

Direct Known Subclasses:

DatagramChannel, Pipe.SinkChannel, Pipe.SourceChannel, ServerSocketChannel, SocketChannel

public abstract class AbstractSelectableChannel
extends SelectableChannel

AbstractSelectableChannel is the base implementation class for selectable channels. It declares methods for registering, unregistering and closing selectable channels. It is thread-safe.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSelectableChannel(SelectorProvider selectorProvider) Constructs a new AbstractSelectableChannel.

Method Summary

Modifier and Type	Method and Description
Object	blockingLock() Gets the object used for the synchronization of register and configureBlocking.
SelectableChannel	configureBlocking(boolean blockingMode) Sets the blocking mode of this channel.
protected void	implCloseChannel() Implements the channel closing behavior.
protected abstract void	implCloseSelectableChannel() Implements the closing function of the SelectableChannel.
protected abstract void	implConfigureBlocking(boolean blocking) Implements the configuration of blocking/non-blocking mode.
boolean	isBlocking() Indicates whether this channel is in blocking mode.
boolean	isRegistered() Indicates whether this channel is registered with one or more selectors.
SelectionKey	keyFor(Selector selector) Gets this channel's selection key for the specified selector.
SelectorProvider	provider() Returns the selector provider that has created this channel.
SelectionKey	register(Selector selector, int interestSet, Object attachment) Registers this channel with the specified selector for the specified interest set.

Methods inherited from class java.nio.channels.SelectableChannel

register, validOps

Methods inherited from class java.nio.channels.spi.AbstractInterruptibleChannel

begin, close, end, isOpen

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.nio.channels.Channel

close, isOpen

Constructor Detail

AbstractSelectableChannel

protected AbstractSelectableChannel(SelectorProvider selectorProvider)

Constructs a new AbstractSelectableChannel.

Parameters:

selectorProvider - the selector provider that creates this channel.

Method Detail

provider

public final SelectorProvider provider()

Returns the selector provider that has created this channel.

Specified by:

provider in class SelectableChannel

Returns:

this channel's selector provider.

See Also:

SelectableChannel.provider()

isRegistered

public final boolean isRegistered()

Indicates whether this channel is registered with one or more selectors.

Specified by:

isRegistered in class SelectableChannel

Returns:

true if this channel is registered with a selector, false otherwise.

keyFor

public final SelectionKey keyFor(Selector selector)

Gets this channel's selection key for the specified selector.

Specified by:

keyFor in class SelectableChannel

Parameters:

selector - the selector with which this channel has been registered.

Returns:

the selection key for the channel or null if this channel has not been registered with selector.

register

public final SelectionKey register(Selector selector,
                                   int interestSet,
                                   Object attachment)
                            throws ClosedChannelException

Registers this channel with the specified selector for the specified interest set. If the channel is already registered with the selector, the interest set is updated to interestSet and the corresponding selection key is returned. If the channel is not yet registered, this method calls the register method of selector and adds the selection key to this channel's key set.

Specified by:

register in class SelectableChannel

Parameters:

selector - the selector with which to register this channel.

interestSet - this channel's interest set.

attachment - the object to attach, can be null.

Returns:

the selection key for this registration.

Throws:

CancelledKeyException - if this channel is registered but its key has been canceled.

ClosedChannelException - if this channel is closed.

IllegalArgumentException - if interestSet is not supported by this channel.

IllegalBlockingModeException - if this channel is in blocking mode.

IllegalSelectorException - if this channel does not have the same provider as the given selector.

implCloseChannel

protected final void implCloseChannel()
                               throws IOException

Implements the channel closing behavior. Calls implCloseSelectableChannel() first, then loops through the list of selection keys and cancels them, which unregisters this channel from all selectors it is registered with.

Specified by:

implCloseChannel in class AbstractInterruptibleChannel

Throws:

IOException - if a problem occurs while closing the channel.

implCloseSelectableChannel

protected abstract void implCloseSelectableChannel()
                                            throws IOException

Implements the closing function of the SelectableChannel. This method is called from implCloseChannel().

Throws:

IOException - if an I/O exception occurs.

isBlocking

public final boolean isBlocking()

Indicates whether this channel is in blocking mode.

Specified by:

isBlocking in class SelectableChannel

Returns:

true if this channel is blocking, false otherwise.

blockingLock

public final Object blockingLock()

Gets the object used for the synchronization of register and configureBlocking.

Specified by:

blockingLock in class SelectableChannel

Returns:

the synchronization object.

configureBlocking

public final SelectableChannel configureBlocking(boolean blockingMode)
                                          throws IOException

Sets the blocking mode of this channel. A call to this method blocks if other calls to this method or to register are executing. The actual setting of the mode is done by calling implConfigureBlocking(boolean).

Specified by:

configureBlocking in class SelectableChannel

Parameters:

blockingMode - true for setting this channel's mode to blocking, false to set it to non-blocking.

Returns:

this channel.

Throws:

ClosedChannelException - if this channel is closed.

IllegalBlockingModeException - if block is true and this channel has been registered with at least one selector.

IOException - if an I/O error occurs.

See Also:

SelectableChannel.configureBlocking(boolean)

implConfigureBlocking

protected abstract void implConfigureBlocking(boolean blocking)
                                       throws IOException

Implements the configuration of blocking/non-blocking mode.

Parameters:

blocking - true for blocking, false for non-blocking.

Throws:

IOException - if an I/O error occurs.