- All Implemented Interfaces:
- Closeable,- AutoCloseable,- Channel,- InterruptibleChannel
- Direct Known Subclasses:
- FileChannel,- SelectableChannel
 This class encapsulates the low-level machinery required to implement
 the asynchronous closing and interruption of channels.  A concrete channel
 class must invoke the begin and end methods
 before and after, respectively, invoking an I/O operation that might block
 indefinitely.  In order to ensure that the end method is always
 invoked, these methods should be used within a
 try ... finally block:
 
    boolean completed = false;
    try {
        begin();
        completed = ...;    // Perform blocking I/O operation
        return ...;         // Return result
    } finally {
        end(completed);
    }
 The completed argument to the end method tells
 whether or not the I/O operation actually completed, that is, whether it had
 any effect that would be visible to the invoker.  In the case of an
 operation that reads bytes, for example, this argument should be
 true if, and only if, some bytes were actually transferred into the
 invoker's target buffer.
 
 A concrete channel class must also implement the implCloseChannel method in such a way that if it is
 invoked while another thread is blocked in a native I/O operation upon the
 channel then that operation will immediately return, either by throwing an
 exception or by returning normally.  If a thread is interrupted or the
 channel upon which it is blocked is asynchronously closed then the channel's
 end method will throw the appropriate exception.
 
 This class performs the synchronization required to implement the Channel specification.  Implementations of the implCloseChannel method need not synchronize against
 other threads that might be attempting to close the channel.  
- Since:
- 1.4
- 
Constructor SummaryConstructorsModifierConstructorDescriptionprotectedInitializes a new instance of this class.
- 
Method SummaryModifier and TypeMethodDescriptionprotected final voidbegin()Marks the beginning of an I/O operation that might block indefinitely.final voidclose()Closes this channel.protected final voidend(boolean completed) Marks the end of an I/O operation that might block indefinitely.protected abstract voidCloses this channel.final booleanisOpen()Tells whether or not this channel is open.
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Constructor Details- 
AbstractInterruptibleChannelprotected AbstractInterruptibleChannel()Initializes a new instance of this class.
 
- 
- 
Method Details- 
closeCloses this channel.If the channel has already been closed then this method returns immediately. Otherwise it marks the channel as closed and then invokes the implCloseChannelmethod in order to complete the close operation.- Specified by:
- closein interface- AutoCloseable
- Specified by:
- closein interface- Channel
- Specified by:
- closein interface- Closeable
- Specified by:
- closein interface- InterruptibleChannel
- Throws:
- IOException- If an I/O error occurs
 
- 
implCloseChannelCloses this 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 while closing the channel
 
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isOpenpublic final boolean isOpen()Description copied from interface:ChannelTells whether or not this channel is open.
- 
beginprotected final void begin()
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endMarks the end of an I/O operation that might block indefinitely.This method should be invoked in tandem with the beginmethod, using atry...finallyblock as shown above, in order to implement asynchronous closing and interruption for this channel.- Parameters:
- completed-- trueif, and only if, the I/O operation completed successfully, that is, had some effect that would be visible to the operation's invoker
- Throws:
- AsynchronousCloseException- If the channel was asynchronously closed
- ClosedByInterruptException- If the thread blocked in the I/O operation was interrupted
 
 
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