1 /*
2 * Copyright (c) 1995, 2019, 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 static {
43 init();
44 }
45
46 private AbstractPlainSocketImpl impl = null;
47 private byte temp[] = new byte[1];
48
49 /**
50 * Creates a new SocketOutputStream. Can only be called
51 * by a Socket. This method needs to hang on to the owner Socket so
52 * that the fd will not be closed.
53 * @param impl the socket output stream implemented
54 */
55 SocketOutputStream(AbstractPlainSocketImpl impl) throws IOException {
56 super(impl.getFileDescriptor());
57 this.impl = impl;
58 }
59
60 /**
61 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
62 * object associated with this file output stream. </p>
63 *
64 * The {@code getChannel} method of {@code SocketOutputStream}
65 * returns {@code null} since it is a socket based stream.</p>
66 *
67 * @return the file channel associated with this file output stream
68 *
69 * @since 1.4
70 * @spec JSR-51
71 */
72 public final FileChannel getChannel() {
73 return null;
74 }
75
76 /**
77 * Writes to the socket.
78 * @param fd the FileDescriptor
79 * @param b the data to be written
80 * @param off the start offset in the data
81 * @param len the number of bytes that are written
82 * @exception IOException If an I/O error has occurred.
83 */
84 private native void socketWrite0(FileDescriptor fd, byte[] b, int off,
85 int len) throws IOException;
86
87 /**
88 * Writes to the socket with appropriate locking of the
89 * FileDescriptor.
90 * @param b the data to be written
91 * @param off the start offset in the data
92 * @param len the number of bytes that are written
93 * @exception IOException If an I/O error has occurred.
94 */
95 private void socketWrite(byte b[], int off, int len) throws IOException {
96
97
98 if (len <= 0 || off < 0 || len > b.length - off) {
99 if (len == 0) {
100 return;
101 }
102 throw new ArrayIndexOutOfBoundsException("len == " + len
103 + " off == " + off + " buffer length == " + b.length);
104 }
105
106 FileDescriptor fd = impl.acquireFD();
107 try {
108 socketWrite0(fd, b, off, len);
109 } catch (SocketException se) {
110 if (impl.isClosedOrPending()) {
111 throw new SocketException("Socket closed");
112 } else {
113 throw se;
114 }
115 } finally {
116 impl.releaseFD();
117 }
118 }
119
120 /**
121 * Writes a byte to the socket.
122 * @param b the data to be written
123 * @exception IOException If an I/O error has occurred.
124 */
125 public void write(int b) throws IOException {
126 temp[0] = (byte)b;
127 socketWrite(temp, 0, 1);
128 }
129
130 /**
131 * Writes the contents of the buffer <i>b</i> to the socket.
132 * @param b the data to be written
133 * @exception SocketException If an I/O error has occurred.
134 */
135 public void write(byte b[]) throws IOException {
136 socketWrite(b, 0, b.length);
137 }
138
139 /**
140 * Writes <i>length</i> bytes from buffer <i>b</i> starting at
141 * offset <i>len</i>.
142 * @param b the data to be written
143 * @param off the start offset in the data
144 * @param len the number of bytes that are written
145 * @exception SocketException If an I/O error has occurred.
146 */
147 public void write(byte b[], int off, int len) throws IOException {
148 socketWrite(b, off, len);
149 }
150
151 /**
152 * Overrides finalize, the fd is closed by the Socket.
153 */
154 @SuppressWarnings({"deprecation", "removal"})
155 protected void finalize() {}
156
157 /**
158 * Perform class load-time initializations.
159 */
160 private static native void init();
161
162 }