001/* Pipe.java --
002   Copyright (C) 2002 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package java.nio.channels;
039
040import java.io.IOException;
041import java.nio.channels.spi.AbstractSelectableChannel;
042import java.nio.channels.spi.SelectorProvider;
043
044
045/**
046 * @author Michael Koch
047 * @since 1.4
048 */
049public abstract class Pipe
050{
051  public abstract static class SinkChannel extends AbstractSelectableChannel
052    implements WritableByteChannel, GatheringByteChannel
053  {
054    /**
055     * Initializes the channel.
056     */
057    protected SinkChannel(SelectorProvider provider)
058    {
059      super(provider);
060    }
061
062    /**
063     * Returns an operation set that is valid on this channel.
064     *
065     * The only valid operation on this channel is @see SelectionKey.OP_WRITE.
066     */
067    public final int validOps()
068    {
069      return SelectionKey.OP_WRITE;
070    }
071  }
072
073  public abstract static class SourceChannel extends AbstractSelectableChannel
074    implements ReadableByteChannel, ScatteringByteChannel
075  {
076    /**
077     * Initializes the channel.
078     */
079    protected SourceChannel(SelectorProvider provider)
080    {
081      super(provider);
082    }
083
084    /**
085     * Returns an operation set that is valid on this channel.
086     *
087     * The only valid operation on this channel is @see SelectionKey.OP_READ.
088     */
089    public final int validOps()
090    {
091      return SelectionKey.OP_READ;
092    }
093  }
094
095  /**
096   * Initializes the pipe.
097   */
098  protected Pipe()
099  {
100  }
101
102  /**
103   * Opens a pipe.
104   *
105   * @exception IOException If an error occurs
106   */
107  public static Pipe open() throws IOException
108  {
109    return SelectorProvider.provider().openPipe();
110  }
111
112  /**
113   * Returns a pipe's sink channel.
114   */
115  public abstract Pipe.SinkChannel sink();
116
117  /**
118   * Returns a pipe's source channel
119   */
120  public abstract Pipe.SourceChannel source();
121}