1 /*
2 * Copyright (c) 1995, 2013, 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} method of {@code SocketInputStream}
71 * returns {@code null} 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 // wrap native call to allow instrumentation
100 /**
101 * Reads into an array of bytes at the specified offset using
102 * the received socket primitive.
103 * @param fd the FileDescriptor
104 * @param b the buffer into which the data is read
105 * @param off the start offset of the data
106 * @param len the maximum number of bytes read
107 * @param timeout the read timeout in ms
108 * @return the actual number of bytes read, -1 is
109 * returned when the end of the stream is reached.
110 * @exception IOException If an I/O error has occurred.
111 */
112 private int socketRead(FileDescriptor fd,
113 byte b[], int off, int len,
114 int timeout)
115 throws IOException {
116 return socketRead0(fd, b, off, len, timeout);
117 }
118
119 /**
120 * Reads into a byte array data from the socket.
121 * @param b the buffer into which the data is read
122 * @return the actual number of bytes read, -1 is
123 * returned when the end of the stream is reached.
124 * @exception IOException If an I/O error has occurred.
125 */
126 public int read(byte b[]) throws IOException {
127 return read(b, 0, b.length);
128 }
129
130 /**
131 * Reads into a byte array <i>b</i> at offset <i>off</i>,
132 * <i>length</i> bytes of data.
133 * @param b the buffer into which the data is read
134 * @param off the start offset of the data
135 * @param length the maximum number of bytes read
136 * @return the actual number of bytes read, -1 is
137 * returned when the end of the stream is reached.
138 * @exception IOException If an I/O error has occurred.
139 */
140 public int read(byte b[], int off, int length) throws IOException {
141 return read(b, off, length, impl.getTimeout());
142 }
143
144 int read(byte b[], int off, int length, int timeout) throws IOException {
145 int n;
146
147 // EOF already encountered
148 if (eof) {
149 return -1;
150 }
151
152 // connection reset
153 if (impl.isConnectionReset()) {
154 throw new SocketException("Connection reset");
155 }
156
157 // bounds check
158 if (length <= 0 || off < 0 || off + length > b.length) {
159 if (length == 0) {
160 return 0;
161 }
162 throw new ArrayIndexOutOfBoundsException();
163 }
164
165 boolean gotReset = false;
166
167 // acquire file descriptor and do the read
168 FileDescriptor fd = impl.acquireFD();
169 try {
170 n = socketRead(fd, b, off, length, timeout);
171 if (n > 0) {
172 return n;
173 }
174 } catch (ConnectionResetException rstExc) {
175 gotReset = true;
176 } finally {
177 impl.releaseFD();
178 }
179
180 /*
181 * We receive a "connection reset" but there may be bytes still
182 * buffered on the socket
183 */
184 if (gotReset) {
185 impl.setConnectionResetPending();
186 impl.acquireFD();
187 try {
188 n = socketRead(fd, b, off, length, timeout);
189 if (n > 0) {
190 return n;
191 }
192 } catch (ConnectionResetException rstExc) {
193 } finally {
194 impl.releaseFD();
195 }
196 }
197
198 /*
199 * If we get here we are at EOF, the socket has been closed,
200 * or the connection has been reset.
201 */
202 if (impl.isClosedOrPending()) {
203 throw new SocketException("Socket closed");
204 }
205 if (impl.isConnectionResetPending()) {
206 impl.setConnectionReset();
207 }
208 if (impl.isConnectionReset()) {
209 throw new SocketException("Connection reset");
210 }
211 eof = true;
212 return -1;
213 }
214
215 /**
216 * Reads a single byte from the socket.
217 */
218 public int read() throws IOException {
219 if (eof) {
220 return -1;
221 }
222 temp = new byte[1];
223 int n = read(temp, 0, 1);
224 if (n <= 0) {
225 return -1;
226 }
227 return temp[0] & 0xff;
228 }
229
230 /**
231 * Skips n bytes of input.
232 * @param numbytes the number of bytes to skip
233 * @return the actual number of bytes skipped.
234 * @exception IOException If an I/O error has occurred.
235 */
236 public long skip(long numbytes) throws IOException {
237 if (numbytes <= 0) {
238 return 0;
239 }
240 long n = numbytes;
241 int buflen = (int) Math.min(1024, n);
242 byte data[] = new byte[buflen];
243 while (n > 0) {
244 int r = read(data, 0, (int) Math.min((long) buflen, n));
245 if (r < 0) {
246 break;
247 }
248 n -= r;
249 }
250 return numbytes - n;
251 }
252
253 /**
254 * Returns the number of bytes that can be read without blocking.
255 * @return the number of immediately available bytes
256 */
257 public int available() throws IOException {
258 return impl.available();
259 }
260
261 /**
262 * Closes the stream.
263 */
264 private boolean closing = false;
265 public void close() throws IOException {
266 // Prevent recursion. See BugId 4484411
267 if (closing)
268 return;
269 closing = true;
270 if (socket != null) {
271 if (!socket.isClosed())
272 socket.close();
273 } else
274 impl.close();
275 closing = false;
276 }
277
278 void setEOF(boolean eof) {
279 this.eof = eof;
280 }
281
282 /**
283 * Overrides finalize, the fd is closed by the Socket.
284 */
285 protected void finalize() {}
286
287 /**
288 * Perform class load-time initializations.
289 */
290 private native static void init();
291 }