java.nio.channels.spi

Class AbstractInterruptibleChannel

Table des matières
  • All Implemented Interfaces:
    Closeable, AutoCloseable, Channel, InterruptibleChannel
    Direct Known Subclasses:
    FileChannel, SelectableChannel

    public abstract class AbstractInterruptibleChannel
extends Object
implements Channel, InterruptibleChannel
    Base implementation class for interruptible channels.

    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 Summary

      Constructors 
      Modifier Constructor and Description
      protected AbstractInterruptibleChannel()
      Initializes a new instance of this class.

        

    • Method Summary

      Methods 
      Modifier and Type Method and Description
      protected void begin()
      Marks the beginning of an I/O operation that might block indefinitely.
      void close()
      Closes this channel.
      protected void end(boolean completed)
      Marks the end of an I/O operation that might block indefinitely.
      protected abstract void implCloseChannel()
      Closes this channel.
      boolean isOpen()
      Tells whether or not this channel is open.

        

    • Constructor Detail

      • AbstractInterruptibleChannel

        protected AbstractInterruptibleChannel()
        Initializes a new instance of this class.

    • Method Detail

      • implCloseChannel

        protected abstract void implCloseChannel()
                                  throws IOException
        Closes this channel.

        This method is invoked by the close method 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

      • isOpen

        public final boolean isOpen()
        Description copied from interface: Channel
        Tells whether or not this channel is open.

        Specified by:
        isOpen in interface Channel
        Returns:
        true if, and only if, this channel is open

      • begin

        protected final void begin()
        Marks the beginning of an I/O operation that might block indefinitely.

        This method should be invoked in tandem with the end method, using a try ... finally block as shown above, in order to implement asynchronous closing and interruption for this channel.

      • end

        protected final void end(boolean completed)
                  throws AsynchronousCloseException
        Marks the end of an I/O operation that might block indefinitely.

        This method should be invoked in tandem with the begin method, using a try ... finally block as shown above, in order to implement asynchronous closing and interruption for this channel.

        Parameters:
        completed - true if, 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

Traduction non disponible

Les API Java ne sont pas encore traduites en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Version en cache

21/11/2024 21:17:08 Cette version de la page est en cache (à la date du 21/11/2024 21:17:08) afin d'accélérer le traitement. Vous pouvez activer le mode utilisateur dans le menu en haut pour afficher la dernère version de la page.

Document créé le 26/10/2006, dernière modification le 04/03/2020
Source du document imprimé : https://www.gaudry.be/java-api-rf-java/nio/channels/spi/abstractinterruptiblechannel.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

  1. Consulter le document html Langue du document :fr Manuel PHP : https://docs.oracle.com, AbstractInterruptibleChannel

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.

Table des matières Haut