J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2006 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 | /** |
| 29 | * This class represents a datagram packet. |
| 30 | * <p> |
| 31 | * Datagram packets are used to implement a connectionless packet |
| 32 | * delivery service. Each message is routed from one machine to |
| 33 | * another based solely on information contained within that packet. |
| 34 | * Multiple packets sent from one machine to another might be routed |
| 35 | * differently, and might arrive in any order. Packet delivery is |
| 36 | * not guaranteed. |
| 37 | * |
| 38 | * @author Pavani Diwanji |
| 39 | * @author Benjamin Renaud |
| 40 | * @since JDK1.0 |
| 41 | */ |
| 42 | public final |
| 43 | class DatagramPacket { |
| 44 | |
| 45 | /** |
| 46 | * Perform class initialization |
| 47 | */ |
| 48 | static { |
| 49 | java.security.AccessController.doPrivileged( |
| 50 | new sun.security.action.LoadLibraryAction("net")); |
| 51 | init(); |
| 52 | } |
| 53 | |
| 54 | /* |
| 55 | * The fields of this class are package-private since DatagramSocketImpl |
| 56 | * classes needs to access them. |
| 57 | */ |
| 58 | byte[] buf; |
| 59 | int offset; |
| 60 | int length; |
| 61 | int bufLength; |
| 62 | InetAddress address; |
| 63 | int port; |
| 64 | |
| 65 | /** |
| 66 | * Constructs a <code>DatagramPacket</code> for receiving packets of |
| 67 | * length <code>length</code>, specifying an offset into the buffer. |
| 68 | * <p> |
| 69 | * The <code>length</code> argument must be less than or equal to |
| 70 | * <code>buf.length</code>. |
| 71 | * |
| 72 | * @param buf buffer for holding the incoming datagram. |
| 73 | * @param offset the offset for the buffer |
| 74 | * @param length the number of bytes to read. |
| 75 | * |
| 76 | * @since 1.2 |
| 77 | */ |
| 78 | public DatagramPacket(byte buf[], int offset, int length) { |
| 79 | setData(buf, offset, length); |
| 80 | this.address = null; |
| 81 | this.port = -1; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Constructs a <code>DatagramPacket</code> for receiving packets of |
| 86 | * length <code>length</code>. |
| 87 | * <p> |
| 88 | * The <code>length</code> argument must be less than or equal to |
| 89 | * <code>buf.length</code>. |
| 90 | * |
| 91 | * @param buf buffer for holding the incoming datagram. |
| 92 | * @param length the number of bytes to read. |
| 93 | */ |
| 94 | public DatagramPacket(byte buf[], int length) { |
| 95 | this (buf, 0, length); |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Constructs a datagram packet for sending packets of length |
| 100 | * <code>length</code> with offset <code>ioffset</code>to the |
| 101 | * specified port number on the specified host. The |
| 102 | * <code>length</code> argument must be less than or equal to |
| 103 | * <code>buf.length</code>. |
| 104 | * |
| 105 | * @param buf the packet data. |
| 106 | * @param offset the packet data offset. |
| 107 | * @param length the packet data length. |
| 108 | * @param address the destination address. |
| 109 | * @param port the destination port number. |
| 110 | * @see java.net.InetAddress |
| 111 | * |
| 112 | * @since 1.2 |
| 113 | */ |
| 114 | public DatagramPacket(byte buf[], int offset, int length, |
| 115 | InetAddress address, int port) { |
| 116 | setData(buf, offset, length); |
| 117 | setAddress(address); |
| 118 | setPort(port); |
| 119 | } |
| 120 | |
| 121 | /** |
| 122 | * Constructs a datagram packet for sending packets of length |
| 123 | * <code>length</code> with offset <code>ioffset</code>to the |
| 124 | * specified port number on the specified host. The |
| 125 | * <code>length</code> argument must be less than or equal to |
| 126 | * <code>buf.length</code>. |
| 127 | * |
| 128 | * @param buf the packet data. |
| 129 | * @param offset the packet data offset. |
| 130 | * @param length the packet data length. |
| 131 | * @param address the destination socket address. |
| 132 | * @throws IllegalArgumentException if address type is not supported |
| 133 | * @see java.net.InetAddress |
| 134 | * |
| 135 | * @since 1.4 |
| 136 | */ |
| 137 | public DatagramPacket(byte buf[], int offset, int length, |
| 138 | SocketAddress address) throws SocketException { |
| 139 | setData(buf, offset, length); |
| 140 | setSocketAddress(address); |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * Constructs a datagram packet for sending packets of length |
| 145 | * <code>length</code> to the specified port number on the specified |
| 146 | * host. The <code>length</code> argument must be less than or equal |
| 147 | * to <code>buf.length</code>. |
| 148 | * |
| 149 | * @param buf the packet data. |
| 150 | * @param length the packet length. |
| 151 | * @param address the destination address. |
| 152 | * @param port the destination port number. |
| 153 | * @see java.net.InetAddress |
| 154 | */ |
| 155 | public DatagramPacket(byte buf[], int length, |
| 156 | InetAddress address, int port) { |
| 157 | this(buf, 0, length, address, port); |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * Constructs a datagram packet for sending packets of length |
| 162 | * <code>length</code> to the specified port number on the specified |
| 163 | * host. The <code>length</code> argument must be less than or equal |
| 164 | * to <code>buf.length</code>. |
| 165 | * |
| 166 | * @param buf the packet data. |
| 167 | * @param length the packet length. |
| 168 | * @param address the destination address. |
| 169 | * @throws IllegalArgumentException if address type is not supported |
| 170 | * @since 1.4 |
| 171 | * @see java.net.InetAddress |
| 172 | */ |
| 173 | public DatagramPacket(byte buf[], int length, |
| 174 | SocketAddress address) throws SocketException { |
| 175 | this(buf, 0, length, address); |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * Returns the IP address of the machine to which this datagram is being |
| 180 | * sent or from which the datagram was received. |
| 181 | * |
| 182 | * @return the IP address of the machine to which this datagram is being |
| 183 | * sent or from which the datagram was received. |
| 184 | * @see java.net.InetAddress |
| 185 | * @see #setAddress(java.net.InetAddress) |
| 186 | */ |
| 187 | public synchronized InetAddress getAddress() { |
| 188 | return address; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * Returns the port number on the remote host to which this datagram is |
| 193 | * being sent or from which the datagram was received. |
| 194 | * |
| 195 | * @return the port number on the remote host to which this datagram is |
| 196 | * being sent or from which the datagram was received. |
| 197 | * @see #setPort(int) |
| 198 | */ |
| 199 | public synchronized int getPort() { |
| 200 | return port; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * Returns the data buffer. The data received or the data to be sent |
| 205 | * starts from the <code>offset</code> in the buffer, |
| 206 | * and runs for <code>length</code> long. |
| 207 | * |
| 208 | * @return the buffer used to receive or send data |
| 209 | * @see #setData(byte[], int, int) |
| 210 | */ |
| 211 | public synchronized byte[] getData() { |
| 212 | return buf; |
| 213 | } |
| 214 | |
| 215 | /** |
| 216 | * Returns the offset of the data to be sent or the offset of the |
| 217 | * data received. |
| 218 | * |
| 219 | * @return the offset of the data to be sent or the offset of the |
| 220 | * data received. |
| 221 | * |
| 222 | * @since 1.2 |
| 223 | */ |
| 224 | public synchronized int getOffset() { |
| 225 | return offset; |
| 226 | } |
| 227 | |
| 228 | /** |
| 229 | * Returns the length of the data to be sent or the length of the |
| 230 | * data received. |
| 231 | * |
| 232 | * @return the length of the data to be sent or the length of the |
| 233 | * data received. |
| 234 | * @see #setLength(int) |
| 235 | */ |
| 236 | public synchronized int getLength() { |
| 237 | return length; |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * Set the data buffer for this packet. This sets the |
| 242 | * data, length and offset of the packet. |
| 243 | * |
| 244 | * @param buf the buffer to set for this packet |
| 245 | * |
| 246 | * @param offset the offset into the data |
| 247 | * |
| 248 | * @param length the length of the data |
| 249 | * and/or the length of the buffer used to receive data |
| 250 | * |
| 251 | * @exception NullPointerException if the argument is null |
| 252 | * |
| 253 | * @see #getData |
| 254 | * @see #getOffset |
| 255 | * @see #getLength |
| 256 | * |
| 257 | * @since 1.2 |
| 258 | */ |
| 259 | public synchronized void setData(byte[] buf, int offset, int length) { |
| 260 | /* this will check to see if buf is null */ |
| 261 | if (length < 0 || offset < 0 || |
| 262 | (length + offset) < 0 || |
| 263 | ((length + offset) > buf.length)) { |
| 264 | throw new IllegalArgumentException("illegal length or offset"); |
| 265 | } |
| 266 | this.buf = buf; |
| 267 | this.length = length; |
| 268 | this.bufLength = length; |
| 269 | this.offset = offset; |
| 270 | } |
| 271 | |
| 272 | /** |
| 273 | * Sets the IP address of the machine to which this datagram |
| 274 | * is being sent. |
| 275 | * @param iaddr the <code>InetAddress</code> |
| 276 | * @since JDK1.1 |
| 277 | * @see #getAddress() |
| 278 | */ |
| 279 | public synchronized void setAddress(InetAddress iaddr) { |
| 280 | address = iaddr; |
| 281 | } |
| 282 | |
| 283 | /** |
| 284 | * Sets the port number on the remote host to which this datagram |
| 285 | * is being sent. |
| 286 | * @param iport the port number |
| 287 | * @since JDK1.1 |
| 288 | * @see #getPort() |
| 289 | */ |
| 290 | public synchronized void setPort(int iport) { |
| 291 | if (iport < 0 || iport > 0xFFFF) { |
| 292 | throw new IllegalArgumentException("Port out of range:"+ iport); |
| 293 | } |
| 294 | port = iport; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * Sets the SocketAddress (usually IP address + port number) of the remote |
| 299 | * host to which this datagram is being sent. |
| 300 | * |
| 301 | * @param address the <code>SocketAddress</code> |
| 302 | * @throws IllegalArgumentException if address is null or is a |
| 303 | * SocketAddress subclass not supported by this socket |
| 304 | * |
| 305 | * @since 1.4 |
| 306 | * @see #getSocketAddress |
| 307 | */ |
| 308 | public synchronized void setSocketAddress(SocketAddress address) { |
| 309 | if (address == null || !(address instanceof InetSocketAddress)) |
| 310 | throw new IllegalArgumentException("unsupported address type"); |
| 311 | InetSocketAddress addr = (InetSocketAddress) address; |
| 312 | if (addr.isUnresolved()) |
| 313 | throw new IllegalArgumentException("unresolved address"); |
| 314 | setAddress(addr.getAddress()); |
| 315 | setPort(addr.getPort()); |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * Gets the SocketAddress (usually IP address + port number) of the remote |
| 320 | * host that this packet is being sent to or is coming from. |
| 321 | * |
| 322 | * @return the <code>SocketAddress</code> |
| 323 | * @since 1.4 |
| 324 | * @see #setSocketAddress |
| 325 | */ |
| 326 | public synchronized SocketAddress getSocketAddress() { |
| 327 | return new InetSocketAddress(getAddress(), getPort()); |
| 328 | } |
| 329 | |
| 330 | /** |
| 331 | * Set the data buffer for this packet. With the offset of |
| 332 | * this DatagramPacket set to 0, and the length set to |
| 333 | * the length of <code>buf</code>. |
| 334 | * |
| 335 | * @param buf the buffer to set for this packet. |
| 336 | * |
| 337 | * @exception NullPointerException if the argument is null. |
| 338 | * |
| 339 | * @see #getLength |
| 340 | * @see #getData |
| 341 | * |
| 342 | * @since JDK1.1 |
| 343 | */ |
| 344 | public synchronized void setData(byte[] buf) { |
| 345 | if (buf == null) { |
| 346 | throw new NullPointerException("null packet buffer"); |
| 347 | } |
| 348 | this.buf = buf; |
| 349 | this.offset = 0; |
| 350 | this.length = buf.length; |
| 351 | this.bufLength = buf.length; |
| 352 | } |
| 353 | |
| 354 | /** |
| 355 | * Set the length for this packet. The length of the packet is |
| 356 | * the number of bytes from the packet's data buffer that will be |
| 357 | * sent, or the number of bytes of the packet's data buffer that |
| 358 | * will be used for receiving data. The length must be lesser or |
| 359 | * equal to the offset plus the length of the packet's buffer. |
| 360 | * |
| 361 | * @param length the length to set for this packet. |
| 362 | * |
| 363 | * @exception IllegalArgumentException if the length is negative |
| 364 | * of if the length is greater than the packet's data buffer |
| 365 | * length. |
| 366 | * |
| 367 | * @see #getLength |
| 368 | * @see #setData |
| 369 | * |
| 370 | * @since JDK1.1 |
| 371 | */ |
| 372 | public synchronized void setLength(int length) { |
| 373 | if ((length + offset) > buf.length || length < 0 || |
| 374 | (length + offset) < 0) { |
| 375 | throw new IllegalArgumentException("illegal length"); |
| 376 | } |
| 377 | this.length = length; |
| 378 | this.bufLength = this.length; |
| 379 | } |
| 380 | |
| 381 | /** |
| 382 | * Perform class load-time initializations. |
| 383 | */ |
| 384 | private native static void init(); |
| 385 | } |