java.nio.channels
Class SelectionKey

java.lang.Object
  java.nio.channels.SelectionKey

Direct Known Subclasses:

AbstractSelectionKey

public abstract class SelectionKey
extends Object

A key that representing the relationship of a channel and the selector.

Field Summary

static int	OP_ACCEPT Interesting operation mask bit for socket-accept operations.
static int	OP_CONNECT Interesting operation mask bit for socket-connect operations.
static int	OP_READ Interesting operation mask bit for read operations.
static int	OP_WRITE Interesting operation mask bit for write operations.

Constructor Summary

protected

SelectionKey() The constructor.

Method Summary

Object	attach(Object anObject) Attaches an object to the key.
Object	attachment() Gets the attached object.
abstract void	cancel() Cancels this key.
abstract SelectableChannel	channel() Gets the channel of this key.
abstract int	interestOps() Gets the interesting operation of this key.
abstract SelectionKey	interestOps(int operations) Sets the interesting operation for this key.
boolean	isAcceptable() Tells whether the channel of this key is interested in accept operation and ready for acceptation.
boolean	isConnectable() Tells whether the channel of this key is interested in connect operation and ready for connection.
boolean	isReadable() Tells whether the channel of this key is interested in read operation and ready for reading.
abstract boolean	isValid() Tells whether the key is valid.
boolean	isWritable() Tells whether the channel of this key is interested in write operation and ready for writing.
abstract int	readyOps() Gets the ready operation.
abstract Selector	selector() Gets the related selector.

Methods inherited from class java.lang.Object

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

Field Detail

OP_ACCEPT

public static final int OP_ACCEPT

Interesting operation mask bit for socket-accept operations.

See Also:

Constant Field Values

OP_CONNECT

public static final int OP_CONNECT

Interesting operation mask bit for socket-connect operations.

See Also:

Constant Field Values

OP_READ

public static final int OP_READ

Interesting operation mask bit for read operations.

See Also:

Constant Field Values

OP_WRITE

public static final int OP_WRITE

Interesting operation mask bit for write operations.

See Also:

Constant Field Values

Constructor Detail

SelectionKey

protected SelectionKey()

The constructor.

Method Detail

attach

public final Object attach(Object anObject)

Attaches an object to the key.

Parameters:

anObject - the object to attach

Returns:

the last attached object

attachment

public final Object attachment()

Gets the attached object.

Returns:

the attached object or null if no object has been attached

cancel

public abstract void cancel()

Cancels this key.

channel

public abstract SelectableChannel channel()

Gets the channel of this key.

Returns:

the channel of this key

interestOps

public abstract int interestOps()

Gets the interesting operation of this key.

Returns:

the interesting operation of this key

Throws:

CancelledKeyException - If the key has been cancelled already

interestOps

public abstract SelectionKey interestOps(int operations)

Sets the interesting operation for this key.

Parameters:

operations - the interesting operation to set

Returns:

this key

Throws:

IllegalArgumentException - if the given operation is not in the key's interesting operation set

CancelledKeyException - If the key has been cancelled already

isAcceptable

public final boolean isAcceptable()

Tells whether the channel of this key is interested in accept operation and ready for acceptation.

Returns:

true if the channel is interested in accept operation and ready for acceptation

Throws:

CancelledKeyException - If the key has been cancelled already

isConnectable

public final boolean isConnectable()

Tells whether the channel of this key is interested in connect operation and ready for connection.

Returns:

true if the channel is interested in connect operation and ready for connection

Throws:

CancelledKeyException - If the key has been cancelled already

isReadable

public final boolean isReadable()

Tells whether the channel of this key is interested in read operation and ready for reading.

Returns:

true if the channel is interested in read operation and ready for reading

Throws:

CancelledKeyException - If the key has been cancelled already

isValid

public abstract boolean isValid()

Tells whether the key is valid.

Returns:

true if the key has not been cancelled

isWritable

public final boolean isWritable()

Tells whether the channel of this key is interested in write operation and ready for writing.

Returns:

true if the channel is interested in write operation and ready for writing

Throws:

CancelledKeyException - If the key has been cancelled already

readyOps

public abstract int readyOps()

Gets the ready operation.

Returns:

the ready operation

Throws:

CancelledKeyException - If the key has been cancelled already

selector

public abstract Selector selector()

Gets the related selector.

Returns:

the related selector