- All Implemented Interfaces:
- Closeable,- AutoCloseable,- Channel,- InterruptibleChannel
- Direct Known Subclasses:
- DatagramChannel,- Pipe.SinkChannel,- Pipe.SourceChannel,- SctpChannel,- SctpMultiChannel,- SctpServerChannel,- ServerSocketChannel,- SocketChannel
 This class defines methods that handle the mechanics of channel
 registration, deregistration, and closing.  It maintains the current
 blocking mode of this channel as well as its current set of selection keys.
 It performs all of the synchronization required to implement the SelectableChannel specification.  Implementations of the
 protected abstract methods defined in this class need not synchronize
 against other threads that might be engaged in the same operations.  
- Since:
- 1.4
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Constructor SummaryConstructorsModifierConstructorDescriptionprotectedAbstractSelectableChannel(SelectorProvider provider) Initializes a new instance of this class.
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Method SummaryModifier and TypeMethodDescriptionfinal ObjectRetrieves the object upon which theconfigureBlockingandregistermethods synchronize.final SelectableChannelconfigureBlocking(boolean block) Adjusts this channel's blocking mode.protected final voidCloses this channel.protected abstract voidCloses this selectable channel.protected abstract voidimplConfigureBlocking(boolean block) Adjusts this channel's blocking mode.final booleanTells whether or not every I/O operation on this channel will block until it completes.final booleanTells whether or not this channel is currently registered with any selectors.final SelectionKeyRetrieves the key representing the channel's registration with the given selector.final SelectorProviderprovider()Returns the provider that created this channel.final SelectionKeyRegisters this channel with the given selector, returning a selection key.Methods declared in class java.nio.channels.SelectableChannelregister, validOpsMethods declared in class java.nio.channels.spi.AbstractInterruptibleChannelbegin, close, end, isOpen
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Constructor Details- 
AbstractSelectableChannelInitializes a new instance of this class.- Parameters:
- provider- The provider that created this channel
 
 
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Method Details- 
providerReturns the provider that created this channel.- Specified by:
- providerin class- SelectableChannel
- Returns:
- The provider that created this channel
 
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isRegisteredpublic final boolean isRegistered()Description copied from class:SelectableChannelTells 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. - Specified by:
- isRegisteredin class- SelectableChannel
- Returns:
- trueif, and only if, this channel is registered
 
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keyForDescription copied from class:SelectableChannelRetrieves the key representing the channel's registration with the given selector.- Specified by:
- keyForin class- SelectableChannel
- Parameters:
- sel- The selector
- Returns:
- The key returned when this channel was last registered with the
          given selector, or nullif this channel is not currently registered with that selector
 
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registerRegisters this channel with the given selector, returning a selection key.This method first verifies that this channel is open and that the given initial interest set is valid. If this channel is already registered with the given selector then the selection key representing that registration is returned after setting its interest set to the given value. Otherwise this channel has not yet been registered with the given selector, so the registermethod of the selector is invoked while holding the appropriate locks. The resulting key is added to this channel's key set before being returned.- Specified by:
- registerin class- SelectableChannel
- Parameters:
- sel- The selector with which this channel is to be registered
- ops- The interest set for the resulting key
- att- The attachment for the resulting key; may be- null
- Returns:
- A key representing the registration of this channel with the given selector
- Throws:
- ClosedSelectorException- If the selector is closed
- IllegalBlockingModeException- If this channel is in blocking mode
- IllegalSelectorException- If this channel was not created by the same provider as the given selector
- CancelledKeyException- If this channel is currently registered with the given selector but the corresponding key has already been cancelled
- IllegalArgumentException- If a bit in the- opsset does not correspond to an operation that is supported by this channel, that is, if- set & ~validOps() != 0
- ClosedChannelException- If this channel is closed
 
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implCloseChannelCloses this channel.This method, which is specified in the AbstractInterruptibleChannelclass and is invoked by theclosemethod, in turn invokes theimplCloseSelectableChannelmethod in order to perform the actual work of closing this channel. It then cancels all of this channel's keys.- Specified by:
- implCloseChannelin class- AbstractInterruptibleChannel
- Throws:
- IOException- If an I/O error occurs while closing the channel
 
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implCloseSelectableChannelCloses this selectable channel.This method is invoked by the closemethod in order to perform the actual work of closing the channel. This method is only invoked if the channel has not yet been closed, and it is never invoked more than once.An implementation of this method must arrange for any other thread that is blocked in an I/O operation upon this channel to return immediately, either by throwing an exception or by returning normally. - Throws:
- IOException- If an I/O error occurs
 
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isBlockingpublic final boolean isBlocking()Description copied from class:SelectableChannelTells 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. - Specified by:
- isBlockingin class- SelectableChannel
- Returns:
- trueif, and only if, this channel is in blocking mode
 
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blockingLockDescription copied from class:SelectableChannelRetrieves the object upon which theconfigureBlockingandregistermethods 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.- Specified by:
- blockingLockin class- SelectableChannel
- Returns:
- The blocking-mode lock object
 
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configureBlockingAdjusts this channel's blocking mode.If the given blocking mode is different from the current blocking mode then this method invokes the implConfigureBlockingmethod, while holding the appropriate locks, in order to change the mode.- Specified by:
- configureBlockingin class- SelectableChannel
- Parameters:
- block- If- truethen this channel will be placed in blocking mode; if- falsethen it will be placed non-blocking mode
- Returns:
- This selectable channel
- Throws:
- ClosedChannelException- If this channel is closed
- IOException- If an I/O error occurs
 
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implConfigureBlockingAdjusts this channel's blocking mode.This method is invoked by the configureBlockingmethod in order to perform the actual work of changing the blocking mode. This method is only invoked if the new mode is different from the current mode.- Parameters:
- block- If- truethen this channel will be placed in blocking mode; if- falsethen it will be placed non-blocking mode
- Throws:
- IOException- If an I/O error occurs
 
 
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