Source for gnu.java.nio.ChannelInputStream

   1: /* ChannelInputStream.java --
   2:    Copyright (C) 2003 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package gnu.java.nio;
  40: 
  41: import java.io.IOException;
  42: import java.io.InputStream;
  43: import java.nio.ByteBuffer;
  44: import java.nio.channels.IllegalBlockingModeException;
  45: import java.nio.channels.ReadableByteChannel;
  46: import java.nio.channels.SelectableChannel;
  47: 
  48: /**
  49:  * @author Michael Koch
  50:  */
  51: public final class ChannelInputStream extends InputStream
  52: {
  53:   private ReadableByteChannel ch;
  54: 
  55:   public ChannelInputStream (ReadableByteChannel ch)
  56:   {
  57:     super();
  58: 
  59:     this.ch = ch;
  60:   }
  61: 
  62:   public int read(byte[] buf, int off, int len) throws IOException
  63:   {
  64:     if (ch instanceof SelectableChannel
  65:         && (! ((SelectableChannel) ch).isBlocking()))
  66:       throw new IllegalBlockingModeException();
  67: 
  68:     ByteBuffer b = ByteBuffer.wrap(buf, off, len);
  69:     return ch.read(b);
  70:   }
  71: 
  72:   public int read() throws IOException
  73:   {
  74:     if (ch instanceof SelectableChannel
  75:         && (! ((SelectableChannel) ch).isBlocking()))
  76:       throw new IllegalBlockingModeException();
  77: 
  78:     ByteBuffer buffer = ByteBuffer.allocate(1);
  79:     int result = ch.read(buffer);
  80: 
  81:     if (result == -1)
  82:       return -1;
  83: 
  84:     if (result == 0)
  85:       throw new IOException("Could not read from channel");
  86: 
  87:     return buffer.get(0) & 0xff;
  88:   }
  89: }