001    /* Pipe.java --
002       Copyright (C) 2002 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package java.nio.channels;
039    
040    import java.io.IOException;
041    import java.nio.channels.spi.AbstractSelectableChannel;
042    import java.nio.channels.spi.SelectorProvider;
043    
044    
045    /**
046     * @author Michael Koch
047     * @since 1.4
048     */
049    public 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    }