java.nio.channels
Class SelectableChannel

java.lang.Object
  java.nio.channels.spi.AbstractInterruptibleChannel
      java.nio.channels.SelectableChannel

All Implemented Interfaces:

Closeable, Channel, InterruptibleChannel

Direct Known Subclasses:

AbstractSelectableChannel

public abstract class SelectableChannel
extends AbstractInterruptibleChannel
implements Channel

A channel that can be detected by a selector. The channel can be registered with some selectors, and when invoke select method of the selectors, the channel can be checked if it is readable, writable, connectable or acceptable according to its interesting operation.

Constructor Summary

protected

SelectableChannel() Default constructor, can be overridden.

Method Summary

abstract Object	blockingLock() Gets the blocking lock which synchronizes the configureBlocking and register methods.
abstract SelectableChannel	configureBlocking(boolean block) Sets blocking mode of the channel.
abstract boolean	isBlocking() Returns if channel is in blocking mode.
abstract boolean	isRegistered() Returns if channel is registered.
abstract SelectionKey	keyFor(Selector sel) Gets the selection key for the channel with the given selector.
abstract SelectorProvider	provider() Gets the provider of the channel.
SelectionKey	register(Selector selector, int operations) Registers with the given selector with a certain interesting operation.
abstract SelectionKey	register(Selector sel, int ops, Object att) Registers with the given selector with a certain interesting operation and an attached object.
abstract int	validOps() Gets the possible interesting operation of the channel.

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

begin, close, end, implCloseChannel, 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

SelectableChannel

protected SelectableChannel()

Default constructor, can be overridden.

Method Detail

blockingLock

public abstract Object blockingLock()

Gets the blocking lock which synchronizes the configureBlocking and register methods.

Returns:

the blocking object as lock

configureBlocking

public abstract SelectableChannel configureBlocking(boolean block)
                                             throws IOException

Sets blocking mode of the channel.

Parameters:

block - true as blocking, false as non-blocking

Returns:

this channel

Throws:

ClosedChannelException - If this channel has been closed

IllegalBlockingModeException - If the channel has been registered

IOException - if I/O error occurs

isBlocking

public abstract boolean isBlocking()

Returns if channel is in blocking mode.

Returns:

true if channel is blocking

isRegistered

public abstract boolean isRegistered()

Returns if channel is registered.

Returns:

true if channel is registered

keyFor

public abstract SelectionKey keyFor(Selector sel)

Gets the selection key for the channel with the given selector.

Parameters:

sel - the selector with which this channel may register

Returns:

the selection key for the channel according to the given selector

provider

public abstract SelectorProvider provider()

Gets the provider of the channel.

Returns:

the provider of the channel

register

public final SelectionKey register(Selector selector,
                                   int operations)
                            throws ClosedChannelException

Registers with the given selector with a certain interesting operation.

Parameters:

selector - the selector with which this channel shall be registered

operations - the interesting operation

Returns:

the selection key indicates the channel

Throws:

ClosedChannelException - if the channel is closed

IllegalBlockingModeException - If the channel is in blocking mode

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

CancelledKeyException - If this channel is registered but its key has been cancelled

IllegalArgumentException - If the operation given is unsupported by this channel

register

public abstract SelectionKey register(Selector sel,
                                      int ops,
                                      Object att)
                               throws ClosedChannelException

Registers with the given selector with a certain interesting operation and an attached object.

Parameters:

sel - the selector with which this channel shall be registered

ops - the interesting operation

att - The attached object, which can be null

Returns:

the selection key indicates the channel

Throws:

ClosedChannelException - if the channel is closed

IllegalBlockingModeException - If the channel is in blocking mode

IllegalSelectorException - If this channel does not have the same provider with the given selector

CancelledKeyException - If this channel is registered but its key has been cancelled

IllegalArgumentException - If the operation given is unsupported by this channel

validOps

public abstract int validOps()

Gets the possible interesting operation of the channel.

Returns:

the possible interesting operation of the channel