1 /*
2 * Copyright (c) 1995, 2010, 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.FileInputStream;
30 import java.io.IOException;
31 import java.nio.channels.FileChannel;
32
33 import sun.net.ConnectionResetException;
34
35 /**
36 * This stream extends FileInputStream to implement a
37 * SocketInputStream. Note that this class should <b>NOT</b> be
38 * public.
39 *
40 * @author Jonathan Payne
41 * @author Arthur van Hoff
42 */
43 class SocketInputStream extends FileInputStream
44 {
45 static {
46 init();
47 }
48
49 private boolean eof;
50 private AbstractPlainSocketImpl impl = null;
51 private byte temp[];
52 private Socket socket = null;
53
54 /**
55 * Creates a new SocketInputStream. Can only be called
56 * by a Socket. This method needs to hang on to the owner Socket so
57 * that the fd will not be closed.
58 * @param impl the implemented socket input stream
59 */
60 SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
61 super(impl.getFileDescriptor());
62 this.impl = impl;
63 socket = impl.getSocket();
64 }
65
66 /**
67 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
68 * object associated with this file input stream.</p>
69 *
70 * The <code>getChannel</code> method of <code>SocketInputStream</code>
71 * returns <code>null</code> since it is a socket based stream.</p>
72 *
73 * @return the file channel associated with this file input stream
74 *
75 * @since 1.4
76 * @spec JSR-51
77 */
78 public final FileChannel getChannel() {
79 return null;
80 }
81
82 /**
83 * Reads into an array of bytes at the specified offset using
84 * the received socket primitive.
85 * @param fd the FileDescriptor
86 * @param b the buffer into which the data is read
87 * @param off the start offset of the data
88 * @param len the maximum number of bytes read
89 * @param timeout the read timeout in ms
90 * @return the actual number of bytes read, -1 is
91 * returned when the end of the stream is reached.
92 * @exception IOException If an I/O error has occurred.
93 */
94 private native int socketRead0(FileDescriptor fd,
95 byte b[], int off, int len,
96 int timeout)
97 throws IOException;
98
99 /**
100 * Reads into a byte array data from the socket.
101 * @param b the buffer into which the data is read
102 * @return the actual number of bytes read, -1 is
103 * returned when the end of the stream is reached.
104 * @exception IOException If an I/O error has occurred.
105 */
106 public int read(byte b[]) throws IOException {
107 return read(b, 0, b.length);
108 }
109
110 /**
111 * Reads into a byte array <i>b</i> at offset <i>off</i>,
112 * <i>length</i> bytes of data.
113 * @param b the buffer into which the data is read
114 * @param off the start offset of the data
115 * @param length the maximum number of bytes read
116 * @return the actual number of bytes read, -1 is
117 * returned when the end of the stream is reached.
118 * @exception IOException If an I/O error has occurred.
119 */
120 public int read(byte b[], int off, int length) throws IOException {
121 return read(b, off, length, impl.getTimeout());
122 }
123
124 int read(byte b[], int off, int length, int timeout) throws IOException {
125 int n;
126
127 // EOF already encountered
128 if (eof) {
129 return -1;
130 }
131
132 // connection reset
133 if (impl.isConnectionReset()) {
134 throw new SocketException("Connection reset");
135 }
136
137 // bounds check
138 if (length <= 0 || off < 0 || off + length > b.length) {
139 if (length == 0) {
140 return 0;
141 }
142 throw new ArrayIndexOutOfBoundsException();
143 }
144
145 boolean gotReset = false;
146
147 // acquire file descriptor and do the read
148 FileDescriptor fd = impl.acquireFD();
149 try {
150 n = socketRead0(fd, b, off, length, timeout);
151 if (n > 0) {
152 return n;
153 }
154 } catch (ConnectionResetException rstExc) {
155 gotReset = true;
156 } finally {
157 impl.releaseFD();
158 }
159
160 /*
161 * We receive a "connection reset" but there may be bytes still
162 * buffered on the socket
163 */
164 if (gotReset) {
165 impl.setConnectionResetPending();
166 impl.acquireFD();
167 try {
168 n = socketRead0(fd, b, off, length, timeout);
169 if (n > 0) {
170 return n;
171 }
172 } catch (ConnectionResetException rstExc) {
173 } finally {
174 impl.releaseFD();
175 }
176 }
177
178 /*
179 * If we get here we are at EOF, the socket has been closed,
180 * or the connection has been reset.
181 */
182 if (impl.isClosedOrPending()) {
183 throw new SocketException("Socket closed");
184 }
185 if (impl.isConnectionResetPending()) {
186 impl.setConnectionReset();
187 }
188 if (impl.isConnectionReset()) {
189 throw new SocketException("Connection reset");
190 }
191 eof = true;
192 return -1;
193 }
194
195 /**
196 * Reads a single byte from the socket.
197 */
198 public int read() throws IOException {
199 if (eof) {
200 return -1;
201 }
202 temp = new byte[1];
203 int n = read(temp, 0, 1);
204 if (n <= 0) {
205 return -1;
206 }
207 return temp[0] & 0xff;
208 }
209
210 /**
211 * Skips n bytes of input.
212 * @param numbytes the number of bytes to skip
213 * @return the actual number of bytes skipped.
214 * @exception IOException If an I/O error has occurred.
215 */
216 public long skip(long numbytes) throws IOException {
217 if (numbytes <= 0) {
218 return 0;
219 }
220 long n = numbytes;
221 int buflen = (int) Math.min(1024, n);
222 byte data[] = new byte[buflen];
223 while (n > 0) {
224 int r = read(data, 0, (int) Math.min((long) buflen, n));
225 if (r < 0) {
226 break;
227 }
228 n -= r;
229 }
230 return numbytes - n;
231 }
232
233 /**
234 * Returns the number of bytes that can be read without blocking.
235 * @return the number of immediately available bytes
236 */
237 public int available() throws IOException {
238 return impl.available();
239 }
240
241 /**
242 * Closes the stream.
243 */
244 private boolean closing = false;
245 public void close() throws IOException {
246 // Prevent recursion. See BugId 4484411
247 if (closing)
248 return;
249 closing = true;
250 if (socket != null) {
251 if (!socket.isClosed())
252 socket.close();
253 } else
254 impl.close();
255 closing = false;
256 }
257
258 void setEOF(boolean eof) {
259 this.eof = eof;
260 }
261
262 /**
263 * Overrides finalize, the fd is closed by the Socket.
264 */
265 protected void finalize() {}
266
267 /**
268 * Perform class load-time initializations.
269 */
270 private native static void init();
271 }