J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any 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 | int n; |
| 122 | |
| 123 | // EOF already encountered |
| 124 | if (eof) { |
| 125 | return -1; |
| 126 | } |
| 127 | |
| 128 | // connection reset |
| 129 | if (impl.isConnectionReset()) { |
| 130 | throw new SocketException("Connection reset"); |
| 131 | } |
| 132 | |
| 133 | // bounds check |
| 134 | if (length <= 0 || off < 0 || off + length > b.length) { |
| 135 | if (length == 0) { |
| 136 | return 0; |
| 137 | } |
| 138 | throw new ArrayIndexOutOfBoundsException(); |
| 139 | } |
| 140 | |
| 141 | boolean gotReset = false; |
| 142 | |
| 143 | // acquire file descriptor and do the read |
| 144 | FileDescriptor fd = impl.acquireFD(); |
| 145 | try { |
| 146 | n = socketRead0(fd, b, off, length, impl.getTimeout()); |
| 147 | if (n > 0) { |
| 148 | return n; |
| 149 | } |
| 150 | } catch (ConnectionResetException rstExc) { |
| 151 | gotReset = true; |
| 152 | } finally { |
| 153 | impl.releaseFD(); |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * We receive a "connection reset" but there may be bytes still |
| 158 | * buffered on the socket |
| 159 | */ |
| 160 | if (gotReset) { |
| 161 | impl.setConnectionResetPending(); |
| 162 | impl.acquireFD(); |
| 163 | try { |
| 164 | n = socketRead0(fd, b, off, length, impl.getTimeout()); |
| 165 | if (n > 0) { |
| 166 | return n; |
| 167 | } |
| 168 | } catch (ConnectionResetException rstExc) { |
| 169 | } finally { |
| 170 | impl.releaseFD(); |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * If we get here we are at EOF, the socket has been closed, |
| 176 | * or the connection has been reset. |
| 177 | */ |
| 178 | if (impl.isClosedOrPending()) { |
| 179 | throw new SocketException("Socket closed"); |
| 180 | } |
| 181 | if (impl.isConnectionResetPending()) { |
| 182 | impl.setConnectionReset(); |
| 183 | } |
| 184 | if (impl.isConnectionReset()) { |
| 185 | throw new SocketException("Connection reset"); |
| 186 | } |
| 187 | eof = true; |
| 188 | return -1; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * Reads a single byte from the socket. |
| 193 | */ |
| 194 | public int read() throws IOException { |
| 195 | if (eof) { |
| 196 | return -1; |
| 197 | } |
| 198 | temp = new byte[1]; |
| 199 | int n = read(temp, 0, 1); |
| 200 | if (n <= 0) { |
| 201 | return -1; |
| 202 | } |
| 203 | return temp[0] & 0xff; |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Skips n bytes of input. |
| 208 | * @param n the number of bytes to skip |
| 209 | * @return the actual number of bytes skipped. |
| 210 | * @exception IOException If an I/O error has occurred. |
| 211 | */ |
| 212 | public long skip(long numbytes) throws IOException { |
| 213 | if (numbytes <= 0) { |
| 214 | return 0; |
| 215 | } |
| 216 | long n = numbytes; |
| 217 | int buflen = (int) Math.min(1024, n); |
| 218 | byte data[] = new byte[buflen]; |
| 219 | while (n > 0) { |
| 220 | int r = read(data, 0, (int) Math.min((long) buflen, n)); |
| 221 | if (r < 0) { |
| 222 | break; |
| 223 | } |
| 224 | n -= r; |
| 225 | } |
| 226 | return numbytes - n; |
| 227 | } |
| 228 | |
| 229 | /** |
| 230 | * Returns the number of bytes that can be read without blocking. |
| 231 | * @return the number of immediately available bytes |
| 232 | */ |
| 233 | public int available() throws IOException { |
| 234 | return impl.available(); |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * Closes the stream. |
| 239 | */ |
| 240 | private boolean closing = false; |
| 241 | public void close() throws IOException { |
| 242 | // Prevent recursion. See BugId 4484411 |
| 243 | if (closing) |
| 244 | return; |
| 245 | closing = true; |
| 246 | if (socket != null) { |
| 247 | if (!socket.isClosed()) |
| 248 | socket.close(); |
| 249 | } else |
| 250 | impl.close(); |
| 251 | closing = false; |
| 252 | } |
| 253 | |
| 254 | void setEOF(boolean eof) { |
| 255 | this.eof = eof; |
| 256 | } |
| 257 | |
| 258 | /** |
| 259 | * Overrides finalize, the fd is closed by the Socket. |
| 260 | */ |
| 261 | protected void finalize() {} |
| 262 | |
| 263 | /** |
| 264 | * Perform class load-time initializations. |
| 265 | */ |
| 266 | private native static void init(); |
| 267 | } |