1 /*
2 * Copyright (c) 1995, 2019, 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
52 /**
53 * Creates a new SocketInputStream. Can only be called
54 * by a Socket. This method needs to hang on to the owner Socket so
55 * that the fd will not be closed.
56 * @param impl the implemented socket input stream
57 */
58 SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
59 super(impl.getFileDescriptor());
60 this.impl = impl;
61 }
62
63 /**
64 * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
65 * object associated with this file input stream.</p>
66 *
67 * The {@code getChannel} method of {@code SocketInputStream}
68 * returns {@code null} since it is a socket based stream.</p>
69 *
70 * @return the file channel associated with this file input stream
71 *
72 * @since 1.4
73 * @spec JSR-51
74 */
75 public final FileChannel getChannel() {
76 return null;
77 }
78
79 /**
80 * Reads into an array of bytes at the specified offset using
81 * the received socket primitive.
82 * @param fd the FileDescriptor
83 * @param b the buffer into which the data is read
84 * @param off the start offset of the data
85 * @param len the maximum number of bytes read
86 * @param timeout the read timeout in ms
87 * @return the actual number of bytes read, -1 is
88 * returned when the end of the stream is reached.
89 * @throws IOException If an I/O error has occurred.
90 */
91 private native int socketRead0(FileDescriptor fd,
92 byte b[], int off, int len,
93 int timeout)
94 throws IOException;
95
96 // wrap native call to allow instrumentation
97 /**
98 * Reads into an array of bytes at the specified offset using
99 * the received socket primitive.
100 * @param fd the FileDescriptor
101 * @param b the buffer into which the data is read
102 * @param off the start offset of the data
103 * @param len the maximum number of bytes read
104 * @param timeout the read timeout in ms
105 * @return the actual number of bytes read, -1 is
106 * returned when the end of the stream is reached.
107 * @throws IOException If an I/O error has occurred.
108 */
109 private int socketRead(FileDescriptor fd,
110 byte b[], int off, int len,
111 int timeout)
112 throws IOException {
113 return socketRead0(fd, b, off, len, timeout);
114 }
115
116 /**
117 * Reads into a byte array data from the socket.
118 * @param b the buffer into which the data is read
119 * @return the actual number of bytes read, -1 is
120 * returned when the end of the stream is reached.
121 * @throws IOException If an I/O error has occurred.
122 */
123 public int read(byte b[]) throws IOException {
124 return read(b, 0, b.length);
125 }
126
127 /**
128 * Reads into a byte array <i>b</i> at offset <i>off</i>,
129 * <i>length</i> bytes of data.
130 * @param b the buffer into which the data is read
131 * @param off the start offset of the data
132 * @param length the maximum number of bytes read
133 * @return the actual number of bytes read, -1 is
134 * returned when the end of the stream is reached.
135 * @throws IOException If an I/O error has occurred.
136 */
137 public int read(byte b[], int off, int length) throws IOException {
138 return read(b, off, length, impl.getTimeout());
139 }
140
141 int read(byte b[], int off, int length, int timeout) throws IOException {
142 int n;
143
144 // EOF already encountered
145 if (eof) {
146 return -1;
147 }
148
149 // connection reset
150 if (impl.isConnectionReset()) {
151 throw new SocketException("Connection reset");
152 }
153
154 // bounds check
155 if (length <= 0 || off < 0 || length > b.length - off) {
156 if (length == 0) {
157 return 0;
158 }
159 throw new ArrayIndexOutOfBoundsException("length == " + length
160 + " off == " + off + " buffer length == " + b.length);
161 }
162
163 // acquire file descriptor and do the read
164 FileDescriptor fd = impl.acquireFD();
165 try {
166 n = socketRead(fd, b, off, length, timeout);
167 if (n > 0) {
168 return n;
169 }
170 } catch (ConnectionResetException rstExc) {
171 impl.setConnectionReset();
172 } finally {
173 impl.releaseFD();
174 }
175
176 /*
177 * If we get here we are at EOF, the socket has been closed,
178 * or the connection has been reset.
179 */
180 if (impl.isClosedOrPending()) {
181 throw new SocketException("Socket closed");
182 }
183 if (impl.isConnectionReset()) {
184 throw new SocketException("Connection reset");
185 }
186 eof = true;
187 return -1;
188 }
189
190 /**
191 * Reads a single byte from the socket.
192 */
193 public int read() throws IOException {
194 if (eof) {
195 return -1;
196 }
197 temp = new byte[1];
198 int n = read(temp, 0, 1);
199 if (n <= 0) {
200 return -1;
201 }
202 return temp[0] & 0xff;
203 }
204
205 /**
206 * Skips n bytes of input.
207 * @param numbytes the number of bytes to skip
208 * @return the actual number of bytes skipped.
209 * @throws IOException If an I/O error has occurred.
210 */
211 public long skip(long numbytes) throws IOException {
212 if (numbytes <= 0) {
213 return 0;
214 }
215 long n = numbytes;
216 int buflen = (int) Math.min(1024, n);
217 byte data[] = new byte[buflen];
218 while (n > 0) {
219 int r = read(data, 0, (int) Math.min((long) buflen, n));
220 if (r < 0) {
221 break;
222 }
223 n -= r;
224 }
225 return numbytes - n;
226 }
227
228 /**
229 * Returns the number of bytes that can be read without blocking.
230 * @return the number of immediately available bytes
231 */
232 public int available() throws IOException {
233 int available = impl.available();
234 return eof ? 0 : available;
235 }
236
237 void setEOF(boolean eof) {
238 this.eof = eof;
239 }
240
241 public void close() throws IOException {
242 // No longer used. Socket.getInputStream returns an
243 // InputStream which calls Socket.close directly
244 assert false;
245 }
246
247 /**
248 * Overrides finalize, the fd is closed by the Socket.
249 */
250 @SuppressWarnings({"deprecation", "removal"})
251 protected void finalize() {}
252
253 /**
254 * Perform class load-time initializations.
255 */
256 private static native void init();
257 }