1 /*
2 * Copyright (c) 1995, 2012, 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.misc.IoTraceContext;
35 import sun.net.ConnectionResetException;
36
37 /**
38 * This stream extends FileInputStream to implement a
39 * SocketInputStream. Note that this class should <b>NOT</b> be
40 * public.
41 *
42 * @author Jonathan Payne
43 * @author Arthur van Hoff
44 */
45 class SocketInputStream extends FileInputStream
46 {
47 static {
48 init();
49 }
50
51 private boolean eof;
52 private AbstractPlainSocketImpl impl = null;
53 private byte temp[];
54 private Socket socket = null;
55
56 /**
57 * Creates a new SocketInputStream. Can only be called
58 * by a Socket. This method needs to hang on to the owner Socket so
59 * that the fd will not be closed.
60 * @param impl the implemented socket input stream
61 */
62 SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
63 super(impl.getFileDescriptor());
64 this.impl = impl;
65 socket = impl.getSocket();
66 }
67
68 /**
69 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
70 * object associated with this file input stream.</p>
71 *
72 * The <code>getChannel</code> method of <code>SocketInputStream</code>
73 * returns <code>null</code> since it is a socket based stream.</p>
74 *
75 * @return the file channel associated with this file input stream
76 *
77 * @since 1.4
78 * @spec JSR-51
79 */
80 public final FileChannel getChannel() {
81 return null;
82 }
83
84 /**
85 * Reads into an array of bytes at the specified offset using
86 * the received socket primitive.
87 * @param fd the FileDescriptor
88 * @param b the buffer into which the data is read
89 * @param off the start offset of the data
90 * @param len the maximum number of bytes read
91 * @param timeout the read timeout in ms
92 * @return the actual number of bytes read, -1 is
93 * returned when the end of the stream is reached.
94 * @exception IOException If an I/O error has occurred.
95 */
96 private native int socketRead0(FileDescriptor fd,
97 byte b[], int off, int len,
98 int timeout)
99 throws IOException;
100
101 /**
102 * Reads into a byte array data from the socket.
103 * @param b the buffer into which the data is read
104 * @return the actual number of bytes read, -1 is
105 * returned when the end of the stream is reached.
106 * @exception IOException If an I/O error has occurred.
107 */
108 public int read(byte b[]) throws IOException {
109 return read(b, 0, b.length);
110 }
111
112 /**
113 * Reads into a byte array <i>b</i> at offset <i>off</i>,
114 * <i>length</i> bytes of data.
115 * @param b the buffer into which the data is read
116 * @param off the start offset of the data
117 * @param length the maximum number of bytes read
118 * @return the actual number of bytes read, -1 is
119 * returned when the end of the stream is reached.
120 * @exception IOException If an I/O error has occurred.
121 */
122 public int read(byte b[], int off, int length) throws IOException {
123 return read(b, off, length, impl.getTimeout());
124 }
125
126 int read(byte b[], int off, int length, int timeout) throws IOException {
127 int n = 0;
128
129 // EOF already encountered
130 if (eof) {
131 return -1;
132 }
133
134 // connection reset
135 if (impl.isConnectionReset()) {
136 throw new SocketException("Connection reset");
137 }
138
139 // bounds check
140 if (length <= 0 || off < 0 || off + length > b.length) {
141 if (length == 0) {
142 return 0;
143 }
144 throw new ArrayIndexOutOfBoundsException();
145 }
146
147 boolean gotReset = false;
148
149 IoTraceContext traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
150 // acquire file descriptor and do the read
151 FileDescriptor fd = impl.acquireFD();
152 try {
153 n = socketRead0(fd, b, off, length, timeout);
154 if (n > 0) {
155 return n;
156 }
157 } catch (ConnectionResetException rstExc) {
158 gotReset = true;
159 } finally {
160 impl.releaseFD();
161 IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
162 }
163
164 /*
165 * We receive a "connection reset" but there may be bytes still
166 * buffered on the socket
167 */
168 if (gotReset) {
169 traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
170 impl.setConnectionResetPending();
171 impl.acquireFD();
172 try {
173 n = socketRead0(fd, b, off, length, timeout);
174 if (n > 0) {
175 return n;
176 }
177 } catch (ConnectionResetException rstExc) {
178 } finally {
179 impl.releaseFD();
180 IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
181 }
182 }
183
184 /*
185 * If we get here we are at EOF, the socket has been closed,
186 * or the connection has been reset.
187 */
188 if (impl.isClosedOrPending()) {
189 throw new SocketException("Socket closed");
190 }
191 if (impl.isConnectionResetPending()) {
192 impl.setConnectionReset();
193 }
194 if (impl.isConnectionReset()) {
195 throw new SocketException("Connection reset");
196 }
197 eof = true;
198 return -1;
199 }
200
201 /**
202 * Reads a single byte from the socket.
203 */
204 public int read() throws IOException {
205 if (eof) {
206 return -1;
207 }
208 temp = new byte[1];
209 int n = read(temp, 0, 1);
210 if (n <= 0) {
211 return -1;
212 }
213 return temp[0] & 0xff;
214 }
215
216 /**
217 * Skips n bytes of input.
218 * @param numbytes the number of bytes to skip
219 * @return the actual number of bytes skipped.
220 * @exception IOException If an I/O error has occurred.
221 */
222 public long skip(long numbytes) throws IOException {
223 if (numbytes <= 0) {
224 return 0;
225 }
226 long n = numbytes;
227 int buflen = (int) Math.min(1024, n);
228 byte data[] = new byte[buflen];
229 while (n > 0) {
230 int r = read(data, 0, (int) Math.min((long) buflen, n));
231 if (r < 0) {
232 break;
233 }
234 n -= r;
235 }
236 return numbytes - n;
237 }
238
239 /**
240 * Returns the number of bytes that can be read without blocking.
241 * @return the number of immediately available bytes
242 */
243 public int available() throws IOException {
244 return impl.available();
245 }
246
247 /**
248 * Closes the stream.
249 */
250 private boolean closing = false;
251 public void close() throws IOException {
252 // Prevent recursion. See BugId 4484411
253 if (closing)
254 return;
255 closing = true;
256 if (socket != null) {
257 if (!socket.isClosed())
258 socket.close();
259 } else
260 impl.close();
261 closing = false;
262 }
263
264 void setEOF(boolean eof) {
265 this.eof = eof;
266 }
267
268 /**
269 * Overrides finalize, the fd is closed by the Socket.
270 */
271 protected void finalize() {}
272
273 /**
274 * Perform class load-time initializations.
275 */
276 private native static void init();
277 }