1 /*
   2  * Copyright (c) 1995, 2007, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.net;
  27 
  28 import java.io.FileDescriptor;
  29 import java.io.FileOutputStream;
  30 import java.io.IOException;
  31 import java.nio.channels.FileChannel;
  32 
  33 /**
  34  * This stream extends FileOutputStream to implement a
  35  * SocketOutputStream. Note that this class should <b>NOT</b> be
  36  * public.
  37  *
  38  * @author      Jonathan Payne
  39  * @author      Arthur van Hoff
  40  */
  41 class SocketOutputStream extends FileOutputStream
  42 {
  43     static {
  44         init();
  45     }
  46 
  47     private AbstractPlainSocketImpl impl = null;
  48     private byte temp[] = new byte[1];
  49     private Socket socket = null;
  50 
  51     /**
  52      * Creates a new SocketOutputStream. Can only be called
  53      * by a Socket. This method needs to hang on to the owner Socket so
  54      * that the fd will not be closed.
  55      * @param impl the socket output stream inplemented
  56      */
  57     SocketOutputStream(AbstractPlainSocketImpl impl) throws IOException {
  58         super(impl.getFileDescriptor());
  59         this.impl = impl;
  60         socket = impl.getSocket();
  61     }
  62 
  63     /**
  64      * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
  65      * object associated with this file output stream. </p>
  66      *
  67      * The <code>getChannel</code> method of <code>SocketOutputStream</code>
  68      * returns <code>null</code> since it is a socket based stream.</p>
  69      *
  70      * @return  the file channel associated with this file output stream
  71      *
  72      * @since 1.4
  73      * @spec JSR-51
  74      */
  75     public final FileChannel getChannel() {
  76         return null;
  77     }
  78 
  79     /**
  80      * Writes to the socket.
  81      * @param fd the FileDescriptor
  82      * @param b the data to be written
  83      * @param off the start offset in the data
  84      * @param len the number of bytes that are written
  85      * @exception IOException If an I/O error has occurred.
  86      */
  87     private native void socketWrite0(FileDescriptor fd, byte[] b, int off,
  88                                      int len) throws IOException;
  89 
  90     /**
  91      * Writes to the socket with appropriate locking of the
  92      * FileDescriptor.
  93      * @param b the data to be written
  94      * @param off the start offset in the data
  95      * @param len the number of bytes that are written
  96      * @exception IOException If an I/O error has occurred.
  97      */
  98     private void socketWrite(byte b[], int off, int len) throws IOException {
  99 
 100         if (len <= 0 || off < 0 || off + len > b.length) {
 101             if (len == 0) {
 102                 return;
 103             }
 104             throw new ArrayIndexOutOfBoundsException();
 105         }
 106 
 107         FileDescriptor fd = impl.acquireFD();
 108         try {
 109             socketWrite0(fd, b, off, len);
 110         } catch (SocketException se) {
 111             if (se instanceof sun.net.ConnectionResetException) {
 112                 impl.setConnectionResetPending();
 113                 se = new SocketException("Connection reset");
 114             }
 115             if (impl.isClosedOrPending()) {
 116                 throw new SocketException("Socket closed");
 117             } else {
 118                 throw se;
 119             }
 120         } finally {
 121             impl.releaseFD();
 122         }
 123     }
 124 
 125     /**
 126      * Writes a byte to the socket.
 127      * @param b the data to be written
 128      * @exception IOException If an I/O error has occurred.
 129      */
 130     public void write(int b) throws IOException {
 131         temp[0] = (byte)b;
 132         socketWrite(temp, 0, 1);
 133     }
 134 
 135     /**
 136      * Writes the contents of the buffer <i>b</i> to the socket.
 137      * @param b the data to be written
 138      * @exception SocketException If an I/O error has occurred.
 139      */
 140     public void write(byte b[]) throws IOException {
 141         socketWrite(b, 0, b.length);
 142     }
 143 
 144     /**
 145      * Writes <i>length</i> bytes from buffer <i>b</i> starting at
 146      * offset <i>len</i>.
 147      * @param b the data to be written
 148      * @param off the start offset in the data
 149      * @param len the number of bytes that are written
 150      * @exception SocketException If an I/O error has occurred.
 151      */
 152     public void write(byte b[], int off, int len) throws IOException {
 153         socketWrite(b, off, len);
 154     }
 155 
 156     /**
 157      * Closes the stream.
 158      */
 159     private boolean closing = false;
 160     public void close() throws IOException {
 161         // Prevent recursion. See BugId 4484411
 162         if (closing)
 163             return;
 164         closing = true;
 165         if (socket != null) {
 166             if (!socket.isClosed())
 167                 socket.close();
 168         } else
 169             impl.close();
 170         closing = false;
 171     }
 172 
 173     /**
 174      * Overrides finalize, the fd is closed by the Socket.
 175      */
 176     protected void finalize() {}
 177 
 178     /**
 179      * Perform class load-time initializations.
 180      */
 181     private native static void init();
 182 
 183 }