1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1995, 2016, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27 package java.net; 28 29 import java.io.FileDescriptor; 30 import java.io.FileInputStream; 31 import java.io.IOException; 32 import java.nio.channels.FileChannel; 33 34 import dalvik.system.BlockGuard; 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 private boolean eof; 48 private AbstractPlainSocketImpl impl = null; 49 private byte temp[]; 50 private Socket socket = null; 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 socket = impl.getSocket(); 62 } 63 64 /** 65 * Returns the unique {@link java.nio.channels.FileChannel FileChannel} 66 * object associated with this file input stream.</p> 67 * 68 * The {@code getChannel} method of {@code SocketInputStream} 69 * returns {@code null} since it is a socket based stream.</p> 70 * 71 * @return the file channel associated with this file input stream 72 * 73 * @since 1.4 74 * @spec JSR-51 75 */ 76 public final FileChannel getChannel() { 77 return null; 78 } 79 80 /** 81 * Reads into an array of bytes at the specified offset using 82 * the received socket primitive. 83 * @param fd the FileDescriptor 84 * @param b the buffer into which the data is read 85 * @param off the start offset of the data 86 * @param len the maximum number of bytes read 87 * @param timeout the read timeout in ms 88 * @return the actual number of bytes read, -1 is 89 * returned when the end of the stream is reached. 90 * @exception IOException If an I/O error has occurred. 91 */ 92 private native int socketRead0(FileDescriptor fd, 93 byte b[], int off, int len, 94 int timeout) 95 throws IOException; 96 97 // wrap native call to allow instrumentation 98 /** 99 * Reads into an array of bytes at the specified offset using 100 * the received socket primitive. 101 * @param fd the FileDescriptor 102 * @param b the buffer into which the data is read 103 * @param off the start offset of the data 104 * @param len the maximum number of bytes read 105 * @param timeout the read timeout in ms 106 * @return the actual number of bytes read, -1 is 107 * returned when the end of the stream is reached. 108 * @exception IOException If an I/O error has occurred. 109 */ 110 private int socketRead(FileDescriptor fd, 111 byte b[], int off, int len, 112 int timeout) 113 throws IOException { 114 return socketRead0(fd, b, off, len, timeout); 115 } 116 117 /** 118 * Reads into a byte array data from the socket. 119 * @param b the buffer into which the data is read 120 * @return the actual number of bytes read, -1 is 121 * returned when the end of the stream is reached. 122 * @exception IOException If an I/O error has occurred. 123 */ 124 public int read(byte b[]) throws IOException { 125 return read(b, 0, b.length); 126 } 127 128 /** 129 * Reads into a byte array <i>b</i> at offset <i>off</i>, 130 * <i>length</i> bytes of data. 131 * @param b the buffer into which the data is read 132 * @param off the start offset of the data 133 * @param length the maximum number of bytes read 134 * @return the actual number of bytes read, -1 is 135 * returned when the end of the stream is reached. 136 * @exception IOException If an I/O error has occurred. 137 */ 138 public int read(byte b[], int off, int length) throws IOException { 139 return read(b, off, length, impl.getTimeout()); 140 } 141 142 int read(byte b[], int off, int length, int timeout) throws IOException { 143 int n; 144 145 // EOF already encountered 146 if (eof) { 147 return -1; 148 } 149 150 // connection reset 151 if (impl.isConnectionReset()) { 152 throw new SocketException("Connection reset"); 153 } 154 155 // bounds check 156 if (length <= 0 || off < 0 || length > b.length - off) { 157 if (length == 0) { 158 return 0; 159 } 160 throw new ArrayIndexOutOfBoundsException("length == " + length 161 + " off == " + off + " buffer length == " + b.length); 162 } 163 164 boolean gotReset = false; 165 166 // acquire file descriptor and do the read 167 FileDescriptor fd = impl.acquireFD(); 168 try { 169 BlockGuard.getThreadPolicy().onNetwork(); 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 // Android-changed: Bug fix, if eof == true, we must indicate that we 259 // have 0 bytes available. 260 if (eof) { 261 return 0; 262 } else { 263 return impl.available(); 264 } 265 } 266 267 /** 268 * Closes the stream. 269 */ 270 private boolean closing = false; 271 public void close() throws IOException { 272 // Prevent recursion. See BugId 4484411 273 if (closing) 274 return; 275 closing = true; 276 if (socket != null) { 277 if (!socket.isClosed()) 278 socket.close(); 279 } else 280 impl.close(); 281 closing = false; 282 } 283 284 void setEOF(boolean eof) { 285 this.eof = eof; 286 } 287 288 /** 289 * Overrides finalize, the fd is closed by the Socket. 290 */ 291 protected void finalize() {} 292 } 293
