SocketOutputStream


1   /*
2    * @(#)SocketOutputStream.java  1.30 03/12/19
3    *
4    * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5    * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6    */
7   
8   package java.net;
9   
10  import java.io.FileDescriptor  ;
11  import java.io.FileOutputStream  ;
12  import java.io.IOException  ;
13  import java.nio.channels.FileChannel  ;
14  
15  /**
16   * This stream extends FileOutputStream to implement a
17   * SocketOutputStream. Note that this class should <b>NOT</b> be
18   * public.
19   *
20   * @version     1.30, 12/19/03
21   * @author  Jonathan Payne
22   * @author  Arthur van Hoff
23   */
24  class SocketOutputStream extends FileOutputStream  
25  {
26      static {
27          init();
28      }
29  
30      private PlainSocketImpl   impl = null;
31      private byte temp[] = new byte[1];
32      private Socket   socket = null;
33      
34      /**
35       * Creates a new SocketOutputStream. Can only be called
36       * by a Socket. This method needs to hang on to the owner Socket so
37       * that the fd will not be closed.
38       * @param impl the socket output stream inplemented
39       */
40      SocketOutputStream(PlainSocketImpl   impl) throws IOException   {
41      super(impl.getFileDescriptor());
42      this.impl = impl;
43      socket = impl.getSocket();
44      }
45  
46      /**
47       * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
48       * object associated with this file output stream. </p>
49       *
50       * The <code>getChannel</code> method of <code>SocketOutputStream</code>
51       * returns <code>null</code> since it is a socket based stream.</p>
52       *
53       * @return  the file channel associated with this file output stream
54       *
55       * @since 1.4
56       * @spec JSR-51
57       */
58      public final FileChannel   getChannel() {
59          return null;
60      }
61  
62      /**
63       * Writes to the socket.
64       * @param fd the FileDescriptor
65       * @param b the data to be written
66       * @param off the start offset in the data
67       * @param len the number of bytes that are written
68       * @exception IOException If an I/O error has occurred.
69       */
70      private native void socketWrite0(FileDescriptor   fd, byte[] b, int off,
71                       int len) throws IOException  ;
72  
73      /**
74       * Writes to the socket with appropriate locking of the 
75       * FileDescriptor.
76       * @param b the data to be written
77       * @param off the start offset in the data
78       * @param len the number of bytes that are written
79       * @exception IOException If an I/O error has occurred.
80       */
81      private void socketWrite(byte b[], int off, int len) throws IOException   {
82  
83      if (len <= 0 || off < 0 || off + len > b.length) {
84          if (len == 0) {
85          return;
86          }
87          throw new ArrayIndexOutOfBoundsException  ();
88      }
89  
90      FileDescriptor   fd = impl.acquireFD();
91      try {
92          socketWrite0(fd, b, off, len);
93      } catch (SocketException   se) {
94          if (se instanceof sun.net.ConnectionResetException) {
95          impl.setConnectionResetPending();
96          se = new SocketException  ("Connection reset");
97          }
98          if (impl.isClosedOrPending()) {
99                  throw new SocketException  ("Socket closed");
100             } else {
101         throw se;
102         }
103     } finally {
104         impl.releaseFD();
105     }
106     }
107 
108     /** 
109      * Writes a byte to the socket. 
110      * @param b the data to be written
111      * @exception IOException If an I/O error has occurred. 
112      */
113     public void write(int b) throws IOException   {
114     temp[0] = (byte)b;
115     socketWrite(temp, 0, 1);
116     }
117 
118     /** 
119      * Writes the contents of the buffer <i>b</i> to the socket.
120      * @param b the data to be written
121      * @exception SocketException If an I/O error has occurred. 
122      */
123     public void write(byte b[]) throws IOException   {
124     socketWrite(b, 0, b.length);
125     }
126 
127     /** 
128      * Writes <i>length</i> bytes from buffer <i>b</i> starting at 
129      * offset <i>len</i>.
130      * @param b the data to be written
131      * @param off the start offset in the data
132      * @param len the number of bytes that are written
133      * @exception SocketException If an I/O error has occurred.
134      */
135     public void write(byte b[], int off, int len) throws IOException   {
136     socketWrite(b, off, len);
137     }
138 
139     /**
140      * Closes the stream.
141      */
142     private boolean closing = false;
143     public void close() throws IOException   {
144     // Prevent recursion. See BugId 4484411
145     if (closing)
146         return;
147     closing = true;
148     if (socket != null) {
149         if (!socket.isClosed())
150         socket.close();
151     } else
152         impl.close();
153     closing = false;
154     }
155 
156     /** 
157      * Overrides finalize, the fd is closed by the Socket.
158      */
159     protected void finalize() {}
160 
161     /**
162      * Perform class load-time initializations.
163      */
164     private native static void init();
165 
166 }
167
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