File	Doc	Category	Size	Date	Package
SelectableChannel.java	API Doc	Java SE 5 API	12443	Fri Aug 26 14:57:10 BST 2005	java.nio.channels

SelectableChannel

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

Fields Summary

Constructors Summary
protected SelectableChannel() Initializes a new instance of this class.

Methods Summary
public abstract java.lang.Object	blockingLock() Retrieves the object upon which the {@link #configureBlocking configureBlocking} and {@link #register register} methods synchronize. This is often useful in the implementation of adaptors that require a specific blocking mode to be maintained for a short period of time. return The blocking-mode lock object
public abstract java.nio.channels.SelectableChannel	configureBlocking(boolean block) Adjusts this channel's blocking mode. If this channel is registered with one or more selectors then an attempt to place it into blocking mode will cause an {@link IllegalBlockingModeException} to be thrown. This method may be invoked at any time. The new blocking mode will only affect I/O operations that are initiated after this method returns. For some implementations this may require blocking until all pending I/O operations are complete. If this method is invoked while another invocation of this method or of the {@link #register(Selector, int) register} method is in progress then it will first block until the other operation is complete. param block If true then this channel will be placed in blocking mode; if false then it will be placed non-blocking mode return This selectable channel throws ClosedChannelException If this channel is closed throws IllegalBlockingModeException If block is true and this channel is registered with one or more selectors throws IOException If an I/O error occurs
public abstract boolean	isBlocking() Tells whether or not every I/O operation on this channel will block until it completes. A newly-created channel is always in blocking mode. If this channel is closed then the value returned by this method is not specified. return true if, and only if, this channel is in blocking mode
public abstract boolean	isRegistered() Tells whether or not this channel is currently registered with any selectors. A newly-created channel is not registered. Due to the inherent delay between key cancellation and channel deregistration, a channel may remain registered for some time after all of its keys have been cancelled. A channel may also remain registered for some time after it is closed. return true if, and only if, this channel is registered
public abstract java.nio.channels.SelectionKey	keyFor(java.nio.channels.Selector sel) Retrieves the key representing the channel's registration with the given selector. return The key returned when this channel was last registered with the given selector, or null if this channel is not currently registered with that selector
public abstract java.nio.channels.spi.SelectorProvider	provider() Returns the provider that created this channel. return The provider that created this channel
public abstract java.nio.channels.SelectionKey	register(java.nio.channels.Selector sel, int ops, java.lang.Object att) Registers this channel with the given selector, returning a selection key. If this channel is currently registered with the given selector then the selection key representing that registration is returned. The key's interest set will have been changed to ops, as if by invoking the {@link SelectionKey#interestOps(int) interestOps(int)} method. If the att argument is not null then the key's attachment will have been set to that value. A {@link CancelledKeyException} will be thrown if the key has already been cancelled. Otherwise this channel has not yet been registered with the given selector, so it is registered and the resulting new key is returned. The key's initial interest set will be ops and its attachment will be att. This method may be invoked at any time. If this method is invoked while another invocation of this method or of the {@link #configureBlocking(boolean) configureBlocking} method is in progress then it will first block until the other operation is complete. This method will then synchronize on the selector's key set and therefore may block if invoked concurrently with another registration or selection operation involving the same selector. If this channel is closed while this operation is in progress then the key returned by this method will have been cancelled and will therefore be invalid. param sel The selector with which this channel is to be registered param ops The interest set for the resulting key param att The attachment for the resulting key; may be null throws ClosedChannelException If this channel is closed throws IllegalBlockingModeException If this channel is in blocking mode throws IllegalSelectorException If this channel was not created by the same provider as the given selector throws CancelledKeyException If this channel is currently registered with the given selector but the corresponding key has already been cancelled throws IllegalArgumentException If a bit in the ops set does not correspond to an operation that is supported by this channel, that is, if set & ~validOps() != 0 return A key representing the registration of this channel with the given selector
public final java.nio.channels.SelectionKey	register(java.nio.channels.Selector sel, int ops) Registers this channel with the given selector, returning a selection key. An invocation of this convenience method of the form sc.register(sel, ops) behaves in exactly the same way as the invocation sc.{@link #register(java.nio.channels.Selector,int,java.lang.Object) register}(sel, ops, null) param sel The selector with which this channel is to be registered param ops The interest set for the resulting key throws ClosedChannelException If this channel is closed throws IllegalBlockingModeException If this channel is in blocking mode throws IllegalSelectorException If this channel was not created by the same provider as the given selector throws CancelledKeyException If this channel is currently registered with the given selector but the corresponding key has already been cancelled throws IllegalArgumentException If a bit in ops does not correspond to an operation that is supported by this channel, that is, if set & ~validOps() != 0 return A key representing the registration of this channel with the given selector return register(sel, ops, null);
public abstract int	validOps() Returns an operation set identifying this channel's supported operations. The bits that are set in this integer value denote exactly the operations that are valid for this channel. This method always returns the same value for a given concrete channel class. return The valid-operation set