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.misc.IoTrace;
34 import sun.net.ConnectionResetException;
35
36 /**
37 * This stream extends FileInputStream to implement a
38 * SocketInputStream. Note that this class should <b>NOT</b> be
39 * public.
40 *
41 * @author Jonathan Payne
42 * @author Arthur van Hoff
43 */
44 class SocketInputStream extends FileInputStream
45 {
46 static {
47 init();
48 }
49
50 private boolean eof;
51 private AbstractPlainSocketImpl impl = null;
52 private byte temp[];
53 private Socket socket = null;
54
55 /**
56 * Creates a new SocketInputStream. Can only be called
57 * by a Socket. This method needs to hang on to the owner Socket so
58 * that the fd will not be closed.
59 * @param impl the implemented socket input stream
60 */
61 SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
62 super(impl.getFileDescriptor());
63 this.impl = impl;
64 socket = impl.getSocket();
65 }
66
67 /**
68 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
69 * object associated with this file input stream.</p>
70 *
71 * The <code>getChannel</code> method of <code>SocketInputStream</code>
72 * returns <code>null</code> since it is a socket based stream.</p>
73 *
74 * @return the file channel associated with this file input stream
75 *
76 * @since 1.4
77 * @spec JSR-51
78 */
79 public final FileChannel getChannel() {
80 return null;
81 }
82
83 /**
84 * Reads into an array of bytes at the specified offset using
85 * the received socket primitive.
86 * @param fd the FileDescriptor
87 * @param b the buffer into which the data is read
88 * @param off the start offset of the data
89 * @param len the maximum number of bytes read
90 * @param timeout the read timeout in ms
91 * @return the actual number of bytes read, -1 is
92 * returned when the end of the stream is reached.
93 * @exception IOException If an I/O error has occurred.
94 */
95 private native int socketRead0(FileDescriptor fd,
96 byte b[], int off, int len,
97 int timeout)
98 throws IOException;
99
100 /**
101 * Reads into a byte array data from the socket.
102 * @param b the buffer into which the data is read
103 * @return the actual number of bytes read, -1 is
104 * returned when the end of the stream is reached.
105 * @exception IOException If an I/O error has occurred.
106 */
107 public int read(byte b[]) throws IOException {
108 return read(b, 0, b.length);
109 }
110
111 /**
112 * Reads into a byte array <i>b</i> at offset <i>off</i>,
113 * <i>length</i> bytes of data.
114 * @param b the buffer into which the data is read
115 * @param off the start offset of the data
116 * @param len the maximum number of bytes read
117 * @return the actual number of bytes read, -1 is
118 * returned when the end of the stream is reached.
119 * @exception IOException If an I/O error has occurred.
120 */
121 public int read(byte b[], int off, int length) throws IOException {
122 return read(b, off, length, impl.getTimeout());
123 }
124
125 int read(byte b[], int off, int length, int timeout) throws IOException {
126 int n = 0;
127
128 // EOF already encountered
129 if (eof) {
130 return -1;
131 }
132
133 // connection reset
134 if (impl.isConnectionReset()) {
135 throw new SocketException("Connection reset");
136 }
137
138 // bounds check
139 if (length <= 0 || off < 0 || off + length > b.length) {
140 if (length == 0) {
141 return 0;
142 }
143 throw new ArrayIndexOutOfBoundsException();
144 }
145
146 boolean gotReset = false;
147
148 Object traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
149 // acquire file descriptor and do the read
150 FileDescriptor fd = impl.acquireFD();
151 try {
152 n = socketRead0(fd, b, off, length, timeout);
153 if (n > 0) {
154 return n;
155 }
156 } catch (ConnectionResetException rstExc) {
157 gotReset = true;
158 } finally {
159 impl.releaseFD();
160 IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
161 }
162
163 /*
164 * We receive a "connection reset" but there may be bytes still
165 * buffered on the socket
166 */
167 if (gotReset) {
168 traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
169 impl.setConnectionResetPending();
170 impl.acquireFD();
171 try {
172 n = socketRead0(fd, b, off, length, timeout);
173 if (n > 0) {
174 return n;
175 }
176 } catch (ConnectionResetException rstExc) {
177 } finally {
178 impl.releaseFD();
179 IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
180 }
181 }
182
183 /*
184 * If we get here we are at EOF, the socket has been closed,
185 * or the connection has been reset.
186 */
187 if (impl.isClosedOrPending()) {
188 throw new SocketException("Socket closed");
189 }
190 if (impl.isConnectionResetPending()) {
191 impl.setConnectionReset();
192 }
193 if (impl.isConnectionReset()) {
194 throw new SocketException("Connection reset");
195 }
196 eof = true;
197 return -1;
198 }
199
200 /**
201 * Reads a single byte from the socket.
202 */
203 public int read() throws IOException {
204 if (eof) {
205 return -1;
206 }
207 temp = new byte[1];
208 int n = read(temp, 0, 1);
209 if (n <= 0) {
210 return -1;
211 }
212 return temp[0] & 0xff;
213 }
214
215 /**
216 * Skips n bytes of input.
217 * @param n the number of bytes to skip
218 * @return the actual number of bytes skipped.
219 * @exception IOException If an I/O error has occurred.
220 */
221 public long skip(long numbytes) throws IOException {
222 if (numbytes <= 0) {
223 return 0;
224 }
225 long n = numbytes;
226 int buflen = (int) Math.min(1024, n);
227 byte data[] = new byte[buflen];
228 while (n > 0) {
229 int r = read(data, 0, (int) Math.min((long) buflen, n));
230 if (r < 0) {
231 break;
232 }
233 n -= r;
234 }
235 return numbytes - n;
236 }
237
238 /**
239 * Returns the number of bytes that can be read without blocking.
240 * @return the number of immediately available bytes
241 */
242 public int available() throws IOException {
243 return impl.available();
244 }
245
246 /**
247 * Closes the stream.
248 */
249 private boolean closing = false;
250 public void close() throws IOException {
251 // Prevent recursion. See BugId 4484411
252 if (closing)
253 return;
254 closing = true;
255 if (socket != null) {
256 if (!socket.isClosed())
257 socket.close();
258 } else
259 impl.close();
260 closing = false;
261 }
262
263 void setEOF(boolean eof) {
264 this.eof = eof;
265 }
266
267 /**
268 * Overrides finalize, the fd is closed by the Socket.
269 */
270 protected void finalize() {}
271
272 /**
273 * Perform class load-time initializations.
274 */
275 private native static void init();
276 }