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