1 /*
2 * Copyright (c) 1995, 2018, 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 static {
45 init();
46 }
47
48 private boolean eof;
49 private AbstractPlainSocketImpl impl = null;
50 private byte[] temp;
51 private Socket socket = null;
52
53 /**
54 * Creates a new SocketInputStream. Can only be called
55 * by a Socket. This method needs to hang on to the owner Socket so
56 * that the fd will not be closed.
57 * @param impl the implemented socket input stream
58 */
59 SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
60 super(impl.getFileDescriptor());
61 this.impl = impl;
62 socket = impl.getSocket();
63 }
64
65 /**
66 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
67 * object associated with this file input stream.</p>
68 *
69 * The {@code getChannel} method of {@code SocketInputStream}
70 * returns {@code null} since it is a socket based stream.</p>
71 *
72 * @return the file channel associated with this file input stream
73 *
74 * @since 1.4
75 * @spec JSR-51
76 */
77 public final FileChannel getChannel() {
78 return null;
79 }
80
81 /**
82 * Reads into an array of bytes at the specified offset using
83 * the received socket primitive.
84 * @param fd the FileDescriptor
85 * @param b the buffer into which the data is read
86 * @param off the start offset of the data
87 * @param len the maximum number of bytes read
88 * @param timeout the read timeout in ms
89 * @return the actual number of bytes read, -1 is
90 * returned when the end of the stream is reached.
91 * @exception IOException If an I/O error has occurred.
92 */
93 private native int socketRead0(FileDescriptor fd,
94 byte[] b, int off, int len,
95 int timeout)
96 throws IOException;
97
98 // wrap native call to allow instrumentation
99 /**
100 * Reads into an array of bytes at the specified offset using
101 * the received socket primitive.
102 * @param fd the FileDescriptor
103 * @param b the buffer into which the data is read
104 * @param off the start offset of the data
105 * @param len the maximum number of bytes read
106 * @param timeout the read timeout in ms
107 * @return the actual number of bytes read, -1 is
108 * returned when the end of the stream is reached.
109 * @exception IOException If an I/O error has occurred.
110 */
111 private int socketRead(FileDescriptor fd,
112 byte[] b, int off, int len,
113 int timeout)
114 throws IOException {
115 return socketRead0(fd, b, off, len, timeout);
116 }
117
118 /**
119 * Reads into a byte array data from the socket.
120 * @param b the buffer into which the data is read
121 * @return the actual number of bytes read, -1 is
122 * returned when the end of the stream is reached.
123 * @exception IOException If an I/O error has occurred.
124 */
125 public int read(byte[] b) throws IOException {
126 return read(b, 0, b.length);
127 }
128
129 /**
130 * Reads into a byte array <i>b</i> at offset <i>off</i>,
131 * <i>length</i> bytes of data.
132 * @param b the buffer into which the data is read
133 * @param off the start offset of the data
134 * @param length the maximum number of bytes read
135 * @return the actual number of bytes read, -1 is
136 * returned when the end of the stream is reached.
137 * @exception IOException If an I/O error has occurred.
138 */
139 public int read(byte[] b, int off, int length) throws IOException {
140 return read(b, off, length, impl.getTimeout());
141 }
142
143 int read(byte[] b, int off, int length, int timeout) throws IOException {
144 int n;
145
146 // EOF already encountered
147 if (eof) {
148 return -1;
149 }
150
151 // connection reset
152 if (impl.isConnectionReset()) {
153 throw new SocketException("Connection reset");
154 }
155
156 // bounds check
157 if (length <= 0 || off < 0 || length > b.length - off) {
158 if (length == 0) {
159 return 0;
160 }
161 throw new ArrayIndexOutOfBoundsException("length == " + length
162 + " off == " + off + " buffer length == " + b.length);
163 }
164
165 // acquire file descriptor and do the read
166 FileDescriptor fd = impl.acquireFD();
167 try {
168 n = socketRead(fd, b, off, length, timeout);
169 if (n > 0) {
170 return n;
171 }
172 } catch (ConnectionResetException rstExc) {
173 impl.setConnectionReset();
174 } finally {
175 impl.releaseFD();
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.isConnectionReset()) {
186 throw new SocketException("Connection reset");
187 }
188 eof = true;
189 return -1;
190 }
191
192 /**
193 * Reads a single byte from the socket.
194 */
195 public int read() throws IOException {
196 if (eof) {
197 return -1;
198 }
199 temp = new byte[1];
200 int n = read(temp, 0, 1);
201 if (n <= 0) {
202 return -1;
203 }
204 return temp[0] & 0xff;
205 }
206
207 /**
208 * Skips n bytes of input.
209 * @param numbytes the number of bytes to skip
210 * @return the actual number of bytes skipped.
211 * @exception IOException If an I/O error has occurred.
212 */
213 public long skip(long numbytes) throws IOException {
214 if (numbytes <= 0) {
215 return 0;
216 }
217 long n = numbytes;
218 int buflen = (int) Math.min(1024, n);
219 byte[] data = new byte[buflen];
220 while (n > 0) {
221 int r = read(data, 0, (int) Math.min((long) buflen, n));
222 if (r < 0) {
223 break;
224 }
225 n -= r;
226 }
227 return numbytes - n;
228 }
229
230 /**
231 * Returns the number of bytes that can be read without blocking.
232 * @return the number of immediately available bytes
233 */
234 public int available() throws IOException {
235 return impl.available();
236 }
237
238 /**
239 * Closes the stream.
240 */
241 private boolean closing = false;
242 public void close() throws IOException {
243 // Prevent recursion. See BugId 4484411
244 if (closing)
245 return;
246 closing = true;
247 if (socket != null) {
248 if (!socket.isClosed())
249 socket.close();
250 } else
251 impl.close();
252 closing = false;
253 }
254
255 void setEOF(boolean eof) {
256 this.eof = eof;
257 }
258
259 /**
260 * Overrides finalize, the fd is closed by the Socket.
261 */
262 @SuppressWarnings({"deprecation", "removal"})
263 protected void finalize() {}
264
265 /**
266 * Perform class load-time initializations.
267 */
268 private static native void init();
269 }