SelectionKey - Android SDK

Summary: Constants | Protected Ctors | Methods | Inherited Methods | [Expand All]

Added in API level 1

public abstract class

SelectionKey

extends Object

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

Known Direct Subclasses

AbstractSelectionKey

Class Overview

A SelectionKey represents the relationship between a channel and a selector for which the channel is registered.

Operation set

An operation set is represented by an integer value. The bits of an operation set represent categories of operations for a key's channel: Accepting socket connections (OP_ACCEPT), connecting with a socket (OP_CONNECT), reading (OP_READ) and writing (OP_WRITE).

Interest set

The interest set is an operation set that defines the operations that a channel is interested in performing.

Ready set

The ready set is an operation set that shows the operations that a channel is ready to execute.

Summary

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

Protected Constructors
	SelectionKey() Constructs a new `SelectionKey`.

Public Methods
final Object	attach(Object anObject) Attaches an object to this key.
final 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 this key's `interest set`.
abstract SelectionKey	interestOps(int operations) Sets the `interest set` for this key.
final boolean	isAcceptable() Indicates whether this key's channel is interested in the accept operation and is ready to accept new connections.
final boolean	isConnectable() Indicates whether this key's channel is interested in the connect operation and is ready to connect.
final boolean	isReadable() Indicates whether this key's channel is interested in the read operation and is ready to read.
abstract boolean	isValid() Indicates whether this key is valid.
final boolean	isWritable() Indicates whether this key's channel is interested in the write operation and is ready to write.
abstract int	readyOps() Gets the set of operations that are ready.
abstract Selector	selector() Gets the selector for which this key's channel is registered.

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of `Class` that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.

Constants

public static final int OP_ACCEPT

Added in API level 1

Interest set mask bit for socket-accept operations.

Constant Value: 16 (0x00000010)

public static final int OP_CONNECT

Added in API level 1

Interest set mask bit for socket-connect operations.

Constant Value: 8 (0x00000008)

public static final int OP_READ

Added in API level 1

Interesting operation mask bit for read operations.

Constant Value: 1 (0x00000001)

public static final int OP_WRITE

Added in API level 1

Interest set mask bit for write operations.

Constant Value: 4 (0x00000004)

Protected Constructors

protected SelectionKey ()

Added in API level 1

Constructs a new SelectionKey.

Public Methods

public final Object attach (Object anObject)

Added in API level 1

Attaches an object to this key. It is acceptable to attach null, this discards the old attachment.

Parameters

anObject	the object to attach, or `null` to discard the current attachment.

Returns

the last attached object or null if no object has been attached.

public final Object attachment ()

Added in API level 1

Gets the attached object.

Returns

the attached object or null if no object has been attached.

public abstract void cancel ()

Added in API level 1

Cancels this key.

A key that has been canceled is no longer valid. Calling this method on an already canceled key does nothing.

Calling this method is safe at any time. The call might block until another ongoing call to a method of this selector has finished. The reason is that it is synchronizing on the key set of the selector. After this call finishes, the key will have been added to the selectors canceled-keys set and will not be included in any future selects of this selector.

public abstract SelectableChannel channel ()

Added in API level 1

Gets the channel of this key.

Returns

the channel of this key.

public abstract int interestOps ()

Added in API level 1

Gets this key's interest set. The returned set has only those bits set that are valid for this key's channel.

Returns

the interest set of this key.

Throws

CancelledKeyException	if the key has already been canceled.

public abstract SelectionKey interestOps (int operations)

Added in API level 1

Sets the interest set for this key.

Parameters

operations	the new interest set.

Returns

this key.

Throws

IllegalArgumentException	if a bit in `operations` is not in the set of `valid operations` of this key's channel.
CancelledKeyException	if the key has already been canceled.

public final boolean isAcceptable ()

Added in API level 1

Indicates whether this key's channel is interested in the accept operation and is ready to accept new connections. A call to this method is equal to executing (readyOps() & OP_ACCEPT) == OP_ACCEPT.

Returns

true if the channel is interested in the accept operation and is ready to accept new connections, false otherwise.

Throws

CancelledKeyException	if the key has already been canceled.

public final boolean isConnectable ()

Added in API level 1

Indicates whether this key's channel is interested in the connect operation and is ready to connect. A call to this method is equal to executing (readyOps() & OP_CONNECT) == OP_CONNECT.

Returns

true if the channel is interested in the connect operation and is ready to connect, false otherwise.

Throws

CancelledKeyException	if the key has already been canceled.

public final boolean isReadable ()

Added in API level 1

Indicates whether this key's channel is interested in the read operation and is ready to read. A call to this method is equal to executing (readyOps() & OP_READ) == OP_READ.

Returns

true if the channel is interested in the read operation and is ready to read, false otherwise.

Throws

CancelledKeyException	if the key has already been canceled.

public abstract boolean isValid ()

Added in API level 1

Indicates whether this key is valid. A key is valid as long as it has not been canceled.

Returns

true if this key has not been canceled, false otherwise.

public final boolean isWritable ()

Added in API level 1

Indicates whether this key's channel is interested in the write operation and is ready to write. A call to this method is equal to executing (readyOps() & OP_WRITE) == OP_WRITE.

Returns

true if the channel is interested in the write operation and is ready to write, false otherwise.

Throws

CancelledKeyException	if the key has already been canceled.

public abstract int readyOps ()

Added in API level 1

Gets the set of operations that are ready. The returned set has only those bits set that are valid for this key's channel.

Returns

the operations for which this key's channel is ready.

Throws

CancelledKeyException	if the key has already been canceled.

public abstract Selector selector ()

Added in API level 1

Gets the selector for which this key's channel is registered.

Returns

the related selector.

Results

Interfaces

Classes

Exceptions

SelectionKey

Class Overview

Operation set

Interest set

Ready set

Summary

Constants

public static final int OP_ACCEPT

public static final int OP_CONNECT

public static final int OP_READ

public static final int OP_WRITE

Protected Constructors

protected SelectionKey ()

Public Methods

public final Object attach (Object anObject)

Parameters

Returns

public final Object attachment ()

Returns

public abstract void cancel ()

public abstract SelectableChannel channel ()

Returns

public abstract int interestOps ()

Returns

Throws

public abstract SelectionKey interestOps (int operations)

Parameters

Returns

Throws

public final boolean isAcceptable ()

Returns

Throws

public final boolean isConnectable ()

Returns

Throws

public final boolean isReadable ()

Returns

Throws

public abstract boolean isValid ()

Returns

public final boolean isWritable ()

Returns

Throws

public abstract int readyOps ()

Returns

Throws

public abstract Selector selector ()

Returns