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.lang; |
| 27 | |
| 28 | import java.io.*; |
| 29 | import java.util.StringTokenizer; |
| 30 | |
| 31 | /** |
| 32 | * Every Java application has a single instance of class |
| 33 | * <code>Runtime</code> that allows the application to interface with |
| 34 | * the environment in which the application is running. The current |
| 35 | * runtime can be obtained from the <code>getRuntime</code> method. |
| 36 | * <p> |
| 37 | * An application cannot create its own instance of this class. |
| 38 | * |
| 39 | * @author unascribed |
| 40 | * @see java.lang.Runtime#getRuntime() |
| 41 | * @since JDK1.0 |
| 42 | */ |
| 43 | |
| 44 | public class Runtime { |
| 45 | private static Runtime currentRuntime = new Runtime(); |
| 46 | |
| 47 | /** |
| 48 | * Returns the runtime object associated with the current Java application. |
| 49 | * Most of the methods of class <code>Runtime</code> are instance |
| 50 | * methods and must be invoked with respect to the current runtime object. |
| 51 | * |
| 52 | * @return the <code>Runtime</code> object associated with the current |
| 53 | * Java application. |
| 54 | */ |
| 55 | public static Runtime getRuntime() { |
| 56 | return currentRuntime; |
| 57 | } |
| 58 | |
| 59 | /** Don't let anyone else instantiate this class */ |
| 60 | private Runtime() {} |
| 61 | |
| 62 | /** |
| 63 | * Terminates the currently running Java virtual machine by initiating its |
| 64 | * shutdown sequence. This method never returns normally. The argument |
| 65 | * serves as a status code; by convention, a nonzero status code indicates |
| 66 | * abnormal termination. |
| 67 | * |
| 68 | * <p> The virtual machine's shutdown sequence consists of two phases. In |
| 69 | * the first phase all registered {@link #addShutdownHook shutdown hooks}, |
| 70 | * if any, are started in some unspecified order and allowed to run |
| 71 | * concurrently until they finish. In the second phase all uninvoked |
| 72 | * finalizers are run if {@link #runFinalizersOnExit finalization-on-exit} |
| 73 | * has been enabled. Once this is done the virtual machine {@link #halt |
| 74 | * halts}. |
| 75 | * |
| 76 | * <p> If this method is invoked after the virtual machine has begun its |
| 77 | * shutdown sequence then if shutdown hooks are being run this method will |
| 78 | * block indefinitely. If shutdown hooks have already been run and on-exit |
| 79 | * finalization has been enabled then this method halts the virtual machine |
| 80 | * with the given status code if the status is nonzero; otherwise, it |
| 81 | * blocks indefinitely. |
| 82 | * |
| 83 | * <p> The <tt>{@link System#exit(int) System.exit}</tt> method is the |
| 84 | * conventional and convenient means of invoking this method. <p> |
| 85 | * |
| 86 | * @param status |
| 87 | * Termination status. By convention, a nonzero status code |
| 88 | * indicates abnormal termination. |
| 89 | * |
| 90 | * @throws SecurityException |
| 91 | * If a security manager is present and its <tt>{@link |
| 92 | * SecurityManager#checkExit checkExit}</tt> method does not permit |
| 93 | * exiting with the specified status |
| 94 | * |
| 95 | * @see java.lang.SecurityException |
| 96 | * @see java.lang.SecurityManager#checkExit(int) |
| 97 | * @see #addShutdownHook |
| 98 | * @see #removeShutdownHook |
| 99 | * @see #runFinalizersOnExit |
| 100 | * @see #halt(int) |
| 101 | */ |
| 102 | public void exit(int status) { |
| 103 | SecurityManager security = System.getSecurityManager(); |
| 104 | if (security != null) { |
| 105 | security.checkExit(status); |
| 106 | } |
| 107 | Shutdown.exit(status); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Registers a new virtual-machine shutdown hook. |
| 112 | * |
| 113 | * <p> The Java virtual machine <i>shuts down</i> in response to two kinds |
| 114 | * of events: |
| 115 | * |
| 116 | * <ul> |
| 117 | * |
| 118 | * <p> <li> The program <i>exits</i> normally, when the last non-daemon |
| 119 | * thread exits or when the <tt>{@link #exit exit}</tt> (equivalently, |
| 120 | * <tt>{@link System#exit(int) System.exit}</tt>) method is invoked, or |
| 121 | * |
| 122 | * <p> <li> The virtual machine is <i>terminated</i> in response to a |
| 123 | * user interrupt, such as typing <tt>^C</tt>, or a system-wide event, |
| 124 | * such as user logoff or system shutdown. |
| 125 | * |
| 126 | * </ul> |
| 127 | * |
| 128 | * <p> A <i>shutdown hook</i> is simply an initialized but unstarted |
| 129 | * thread. When the virtual machine begins its shutdown sequence it will |
| 130 | * start all registered shutdown hooks in some unspecified order and let |
| 131 | * them run concurrently. When all the hooks have finished it will then |
| 132 | * run all uninvoked finalizers if finalization-on-exit has been enabled. |
| 133 | * Finally, the virtual machine will halt. Note that daemon threads will |
| 134 | * continue to run during the shutdown sequence, as will non-daemon threads |
| 135 | * if shutdown was initiated by invoking the <tt>{@link #exit exit}</tt> |
| 136 | * method. |
| 137 | * |
| 138 | * <p> Once the shutdown sequence has begun it can be stopped only by |
| 139 | * invoking the <tt>{@link #halt halt}</tt> method, which forcibly |
| 140 | * terminates the virtual machine. |
| 141 | * |
| 142 | * <p> Once the shutdown sequence has begun it is impossible to register a |
| 143 | * new shutdown hook or de-register a previously-registered hook. |
| 144 | * Attempting either of these operations will cause an |
| 145 | * <tt>{@link IllegalStateException}</tt> to be thrown. |
| 146 | * |
| 147 | * <p> Shutdown hooks run at a delicate time in the life cycle of a virtual |
| 148 | * machine and should therefore be coded defensively. They should, in |
| 149 | * particular, be written to be thread-safe and to avoid deadlocks insofar |
| 150 | * as possible. They should also not rely blindly upon services that may |
| 151 | * have registered their own shutdown hooks and therefore may themselves in |
| 152 | * the process of shutting down. Attempts to use other thread-based |
| 153 | * services such as the AWT event-dispatch thread, for example, may lead to |
| 154 | * deadlocks. |
| 155 | * |
| 156 | * <p> Shutdown hooks should also finish their work quickly. When a |
| 157 | * program invokes <tt>{@link #exit exit}</tt> the expectation is |
| 158 | * that the virtual machine will promptly shut down and exit. When the |
| 159 | * virtual machine is terminated due to user logoff or system shutdown the |
| 160 | * underlying operating system may only allow a fixed amount of time in |
| 161 | * which to shut down and exit. It is therefore inadvisable to attempt any |
| 162 | * user interaction or to perform a long-running computation in a shutdown |
| 163 | * hook. |
| 164 | * |
| 165 | * <p> Uncaught exceptions are handled in shutdown hooks just as in any |
| 166 | * other thread, by invoking the <tt>{@link ThreadGroup#uncaughtException |
| 167 | * uncaughtException}</tt> method of the thread's <tt>{@link |
| 168 | * ThreadGroup}</tt> object. The default implementation of this method |
| 169 | * prints the exception's stack trace to <tt>{@link System#err}</tt> and |
| 170 | * terminates the thread; it does not cause the virtual machine to exit or |
| 171 | * halt. |
| 172 | * |
| 173 | * <p> In rare circumstances the virtual machine may <i>abort</i>, that is, |
| 174 | * stop running without shutting down cleanly. This occurs when the |
| 175 | * virtual machine is terminated externally, for example with the |
| 176 | * <tt>SIGKILL</tt> signal on Unix or the <tt>TerminateProcess</tt> call on |
| 177 | * Microsoft Windows. The virtual machine may also abort if a native |
| 178 | * method goes awry by, for example, corrupting internal data structures or |
| 179 | * attempting to access nonexistent memory. If the virtual machine aborts |
| 180 | * then no guarantee can be made about whether or not any shutdown hooks |
| 181 | * will be run. <p> |
| 182 | * |
| 183 | * @param hook |
| 184 | * An initialized but unstarted <tt>{@link Thread}</tt> object |
| 185 | * |
| 186 | * @throws IllegalArgumentException |
| 187 | * If the specified hook has already been registered, |
| 188 | * or if it can be determined that the hook is already running or |
| 189 | * has already been run |
| 190 | * |
| 191 | * @throws IllegalStateException |
| 192 | * If the virtual machine is already in the process |
| 193 | * of shutting down |
| 194 | * |
| 195 | * @throws SecurityException |
| 196 | * If a security manager is present and it denies |
| 197 | * <tt>{@link RuntimePermission}("shutdownHooks")</tt> |
| 198 | * |
| 199 | * @see #removeShutdownHook |
| 200 | * @see #halt(int) |
| 201 | * @see #exit(int) |
| 202 | * @since 1.3 |
| 203 | */ |
| 204 | public void addShutdownHook(Thread hook) { |
| 205 | SecurityManager sm = System.getSecurityManager(); |
| 206 | if (sm != null) { |
| 207 | sm.checkPermission(new RuntimePermission("shutdownHooks")); |
| 208 | } |
| 209 | ApplicationShutdownHooks.add(hook); |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * De-registers a previously-registered virtual-machine shutdown hook. <p> |
| 214 | * |
| 215 | * @param hook the hook to remove |
| 216 | * @return <tt>true</tt> if the specified hook had previously been |
| 217 | * registered and was successfully de-registered, <tt>false</tt> |
| 218 | * otherwise. |
| 219 | * |
| 220 | * @throws IllegalStateException |
| 221 | * If the virtual machine is already in the process of shutting |
| 222 | * down |
| 223 | * |
| 224 | * @throws SecurityException |
| 225 | * If a security manager is present and it denies |
| 226 | * <tt>{@link RuntimePermission}("shutdownHooks")</tt> |
| 227 | * |
| 228 | * @see #addShutdownHook |
| 229 | * @see #exit(int) |
| 230 | * @since 1.3 |
| 231 | */ |
| 232 | public boolean removeShutdownHook(Thread hook) { |
| 233 | SecurityManager sm = System.getSecurityManager(); |
| 234 | if (sm != null) { |
| 235 | sm.checkPermission(new RuntimePermission("shutdownHooks")); |
| 236 | } |
| 237 | return ApplicationShutdownHooks.remove(hook); |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * Forcibly terminates the currently running Java virtual machine. This |
| 242 | * method never returns normally. |
| 243 | * |
| 244 | * <p> This method should be used with extreme caution. Unlike the |
| 245 | * <tt>{@link #exit exit}</tt> method, this method does not cause shutdown |
| 246 | * hooks to be started and does not run uninvoked finalizers if |
| 247 | * finalization-on-exit has been enabled. If the shutdown sequence has |
| 248 | * already been initiated then this method does not wait for any running |
| 249 | * shutdown hooks or finalizers to finish their work. <p> |
| 250 | * |
| 251 | * @param status |
| 252 | * Termination status. By convention, a nonzero status code |
| 253 | * indicates abnormal termination. If the <tt>{@link Runtime#exit |
| 254 | * exit}</tt> (equivalently, <tt>{@link System#exit(int) |
| 255 | * System.exit}</tt>) method has already been invoked then this |
| 256 | * status code will override the status code passed to that method. |
| 257 | * |
| 258 | * @throws SecurityException |
| 259 | * If a security manager is present and its <tt>{@link |
| 260 | * SecurityManager#checkExit checkExit}</tt> method does not permit |
| 261 | * an exit with the specified status |
| 262 | * |
| 263 | * @see #exit |
| 264 | * @see #addShutdownHook |
| 265 | * @see #removeShutdownHook |
| 266 | * @since 1.3 |
| 267 | */ |
| 268 | public void halt(int status) { |
| 269 | SecurityManager sm = System.getSecurityManager(); |
| 270 | if (sm != null) { |
| 271 | sm.checkExit(status); |
| 272 | } |
| 273 | Shutdown.halt(status); |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | * Enable or disable finalization on exit; doing so specifies that the |
| 278 | * finalizers of all objects that have finalizers that have not yet been |
| 279 | * automatically invoked are to be run before the Java runtime exits. |
| 280 | * By default, finalization on exit is disabled. |
| 281 | * |
| 282 | * <p>If there is a security manager, |
| 283 | * its <code>checkExit</code> method is first called |
| 284 | * with 0 as its argument to ensure the exit is allowed. |
| 285 | * This could result in a SecurityException. |
| 286 | * |
| 287 | * @param value true to enable finalization on exit, false to disable |
| 288 | * @deprecated This method is inherently unsafe. It may result in |
| 289 | * finalizers being called on live objects while other threads are |
| 290 | * concurrently manipulating those objects, resulting in erratic |
| 291 | * behavior or deadlock. |
| 292 | * |
| 293 | * @throws SecurityException |
| 294 | * if a security manager exists and its <code>checkExit</code> |
| 295 | * method doesn't allow the exit. |
| 296 | * |
| 297 | * @see java.lang.Runtime#exit(int) |
| 298 | * @see java.lang.Runtime#gc() |
| 299 | * @see java.lang.SecurityManager#checkExit(int) |
| 300 | * @since JDK1.1 |
| 301 | */ |
| 302 | @Deprecated |
| 303 | public static void runFinalizersOnExit(boolean value) { |
| 304 | SecurityManager security = System.getSecurityManager(); |
| 305 | if (security != null) { |
| 306 | try { |
| 307 | security.checkExit(0); |
| 308 | } catch (SecurityException e) { |
| 309 | throw new SecurityException("runFinalizersOnExit"); |
| 310 | } |
| 311 | } |
| 312 | Shutdown.setRunFinalizersOnExit(value); |
| 313 | } |
| 314 | |
| 315 | /** |
| 316 | * Executes the specified string command in a separate process. |
| 317 | * |
| 318 | * <p>This is a convenience method. An invocation of the form |
| 319 | * <tt>exec(command)</tt> |
| 320 | * behaves in exactly the same way as the invocation |
| 321 | * <tt>{@link #exec(String, String[], File) exec}(command, null, null)</tt>. |
| 322 | * |
| 323 | * @param command a specified system command. |
| 324 | * |
| 325 | * @return A new {@link Process} object for managing the subprocess |
| 326 | * |
| 327 | * @throws SecurityException |
| 328 | * If a security manager exists and its |
| 329 | * {@link SecurityManager#checkExec checkExec} |
| 330 | * method doesn't allow creation of the subprocess |
| 331 | * |
| 332 | * @throws IOException |
| 333 | * If an I/O error occurs |
| 334 | * |
| 335 | * @throws NullPointerException |
| 336 | * If <code>command</code> is <code>null</code> |
| 337 | * |
| 338 | * @throws IllegalArgumentException |
| 339 | * If <code>command</code> is empty |
| 340 | * |
| 341 | * @see #exec(String[], String[], File) |
| 342 | * @see ProcessBuilder |
| 343 | */ |
| 344 | public Process exec(String command) throws IOException { |
| 345 | return exec(command, null, null); |
| 346 | } |
| 347 | |
| 348 | /** |
| 349 | * Executes the specified string command in a separate process with the |
| 350 | * specified environment. |
| 351 | * |
| 352 | * <p>This is a convenience method. An invocation of the form |
| 353 | * <tt>exec(command, envp)</tt> |
| 354 | * behaves in exactly the same way as the invocation |
| 355 | * <tt>{@link #exec(String, String[], File) exec}(command, envp, null)</tt>. |
| 356 | * |
| 357 | * @param command a specified system command. |
| 358 | * |
| 359 | * @param envp array of strings, each element of which |
| 360 | * has environment variable settings in the format |
| 361 | * <i>name</i>=<i>value</i>, or |
| 362 | * <tt>null</tt> if the subprocess should inherit |
| 363 | * the environment of the current process. |
| 364 | * |
| 365 | * @return A new {@link Process} object for managing the subprocess |
| 366 | * |
| 367 | * @throws SecurityException |
| 368 | * If a security manager exists and its |
| 369 | * {@link SecurityManager#checkExec checkExec} |
| 370 | * method doesn't allow creation of the subprocess |
| 371 | * |
| 372 | * @throws IOException |
| 373 | * If an I/O error occurs |
| 374 | * |
| 375 | * @throws NullPointerException |
| 376 | * If <code>command</code> is <code>null</code>, |
| 377 | * or one of the elements of <code>envp</code> is <code>null</code> |
| 378 | * |
| 379 | * @throws IllegalArgumentException |
| 380 | * If <code>command</code> is empty |
| 381 | * |
| 382 | * @see #exec(String[], String[], File) |
| 383 | * @see ProcessBuilder |
| 384 | */ |
| 385 | public Process exec(String command, String[] envp) throws IOException { |
| 386 | return exec(command, envp, null); |
| 387 | } |
| 388 | |
| 389 | /** |
| 390 | * Executes the specified string command in a separate process with the |
| 391 | * specified environment and working directory. |
| 392 | * |
| 393 | * <p>This is a convenience method. An invocation of the form |
| 394 | * <tt>exec(command, envp, dir)</tt> |
| 395 | * behaves in exactly the same way as the invocation |
| 396 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, dir)</tt>, |
| 397 | * where <code>cmdarray</code> is an array of all the tokens in |
| 398 | * <code>command</code>. |
| 399 | * |
| 400 | * <p>More precisely, the <code>command</code> string is broken |
| 401 | * into tokens using a {@link StringTokenizer} created by the call |
| 402 | * <code>new {@link StringTokenizer}(command)</code> with no |
| 403 | * further modification of the character categories. The tokens |
| 404 | * produced by the tokenizer are then placed in the new string |
| 405 | * array <code>cmdarray</code>, in the same order. |
| 406 | * |
| 407 | * @param command a specified system command. |
| 408 | * |
| 409 | * @param envp array of strings, each element of which |
| 410 | * has environment variable settings in the format |
| 411 | * <i>name</i>=<i>value</i>, or |
| 412 | * <tt>null</tt> if the subprocess should inherit |
| 413 | * the environment of the current process. |
| 414 | * |
| 415 | * @param dir the working directory of the subprocess, or |
| 416 | * <tt>null</tt> if the subprocess should inherit |
| 417 | * the working directory of the current process. |
| 418 | * |
| 419 | * @return A new {@link Process} object for managing the subprocess |
| 420 | * |
| 421 | * @throws SecurityException |
| 422 | * If a security manager exists and its |
| 423 | * {@link SecurityManager#checkExec checkExec} |
| 424 | * method doesn't allow creation of the subprocess |
| 425 | * |
| 426 | * @throws IOException |
| 427 | * If an I/O error occurs |
| 428 | * |
| 429 | * @throws NullPointerException |
| 430 | * If <code>command</code> is <code>null</code>, |
| 431 | * or one of the elements of <code>envp</code> is <code>null</code> |
| 432 | * |
| 433 | * @throws IllegalArgumentException |
| 434 | * If <code>command</code> is empty |
| 435 | * |
| 436 | * @see ProcessBuilder |
| 437 | * @since 1.3 |
| 438 | */ |
| 439 | public Process exec(String command, String[] envp, File dir) |
| 440 | throws IOException { |
| 441 | if (command.length() == 0) |
| 442 | throw new IllegalArgumentException("Empty command"); |
| 443 | |
| 444 | StringTokenizer st = new StringTokenizer(command); |
| 445 | String[] cmdarray = new String[st.countTokens()]; |
| 446 | for (int i = 0; st.hasMoreTokens(); i++) |
| 447 | cmdarray[i] = st.nextToken(); |
| 448 | return exec(cmdarray, envp, dir); |
| 449 | } |
| 450 | |
| 451 | /** |
| 452 | * Executes the specified command and arguments in a separate process. |
| 453 | * |
| 454 | * <p>This is a convenience method. An invocation of the form |
| 455 | * <tt>exec(cmdarray)</tt> |
| 456 | * behaves in exactly the same way as the invocation |
| 457 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, null, null)</tt>. |
| 458 | * |
| 459 | * @param cmdarray array containing the command to call and |
| 460 | * its arguments. |
| 461 | * |
| 462 | * @return A new {@link Process} object for managing the subprocess |
| 463 | * |
| 464 | * @throws SecurityException |
| 465 | * If a security manager exists and its |
| 466 | * {@link SecurityManager#checkExec checkExec} |
| 467 | * method doesn't allow creation of the subprocess |
| 468 | * |
| 469 | * @throws IOException |
| 470 | * If an I/O error occurs |
| 471 | * |
| 472 | * @throws NullPointerException |
| 473 | * If <code>cmdarray</code> is <code>null</code>, |
| 474 | * or one of the elements of <code>cmdarray</code> is <code>null</code> |
| 475 | * |
| 476 | * @throws IndexOutOfBoundsException |
| 477 | * If <code>cmdarray</code> is an empty array |
| 478 | * (has length <code>0</code>) |
| 479 | * |
| 480 | * @see ProcessBuilder |
| 481 | */ |
| 482 | public Process exec(String cmdarray[]) throws IOException { |
| 483 | return exec(cmdarray, null, null); |
| 484 | } |
| 485 | |
| 486 | /** |
| 487 | * Executes the specified command and arguments in a separate process |
| 488 | * with the specified environment. |
| 489 | * |
| 490 | * <p>This is a convenience method. An invocation of the form |
| 491 | * <tt>exec(cmdarray, envp)</tt> |
| 492 | * behaves in exactly the same way as the invocation |
| 493 | * <tt>{@link #exec(String[], String[], File) exec}(cmdarray, envp, null)</tt>. |
| 494 | * |
| 495 | * @param cmdarray array containing the command to call and |
| 496 | * its arguments. |
| 497 | * |
| 498 | * @param envp array of strings, each element of which |
| 499 | * has environment variable settings in the format |
| 500 | * <i>name</i>=<i>value</i>, or |
| 501 | * <tt>null</tt> if the subprocess should inherit |
| 502 | * the environment of the current process. |
| 503 | * |
| 504 | * @return A new {@link Process} object for managing the subprocess |
| 505 | * |
| 506 | * @throws SecurityException |
| 507 | * If a security manager exists and its |
| 508 | * {@link SecurityManager#checkExec checkExec} |
| 509 | * method doesn't allow creation of the subprocess |
| 510 | * |
| 511 | * @throws IOException |
| 512 | * If an I/O error occurs |
| 513 | * |
| 514 | * @throws NullPointerException |
| 515 | * If <code>cmdarray</code> is <code>null</code>, |
| 516 | * or one of the elements of <code>cmdarray</code> is <code>null</code>, |
| 517 | * or one of the elements of <code>envp</code> is <code>null</code> |
| 518 | * |
| 519 | * @throws IndexOutOfBoundsException |
| 520 | * If <code>cmdarray</code> is an empty array |
| 521 | * (has length <code>0</code>) |
| 522 | * |
| 523 | * @see ProcessBuilder |
| 524 | */ |
| 525 | public Process exec(String[] cmdarray, String[] envp) throws IOException { |
| 526 | return exec(cmdarray, envp, null); |
| 527 | } |
| 528 | |
| 529 | |
| 530 | /** |
| 531 | * Executes the specified command and arguments in a separate process with |
| 532 | * the specified environment and working directory. |
| 533 | * |
| 534 | * <p>Given an array of strings <code>cmdarray</code>, representing the |
| 535 | * tokens of a command line, and an array of strings <code>envp</code>, |
| 536 | * representing "environment" variable settings, this method creates |
| 537 | * a new process in which to execute the specified command. |
| 538 | * |
| 539 | * <p>This method checks that <code>cmdarray</code> is a valid operating |
| 540 | * system command. Which commands are valid is system-dependent, |
| 541 | * but at the very least the command must be a non-empty list of |
| 542 | * non-null strings. |
| 543 | * |
| 544 | * <p>If <tt>envp</tt> is <tt>null</tt>, the subprocess inherits the |
| 545 | * environment settings of the current process. |
| 546 | * |
| 547 | * <p>{@link ProcessBuilder#start()} is now the preferred way to |
| 548 | * start a process with a modified environment. |
| 549 | * |
| 550 | * <p>The working directory of the new subprocess is specified by <tt>dir</tt>. |
| 551 | * If <tt>dir</tt> is <tt>null</tt>, the subprocess inherits the |
| 552 | * current working directory of the current process. |
| 553 | * |
| 554 | * <p>If a security manager exists, its |
| 555 | * {@link SecurityManager#checkExec checkExec} |
| 556 | * method is invoked with the first component of the array |
| 557 | * <code>cmdarray</code> as its argument. This may result in a |
| 558 | * {@link SecurityException} being thrown. |
| 559 | * |
| 560 | * <p>Starting an operating system process is highly system-dependent. |
| 561 | * Among the many things that can go wrong are: |
| 562 | * <ul> |
| 563 | * <li>The operating system program file was not found. |
| 564 | * <li>Access to the program file was denied. |
| 565 | * <li>The working directory does not exist. |
| 566 | * </ul> |
| 567 | * |
| 568 | * <p>In such cases an exception will be thrown. The exact nature |
| 569 | * of the exception is system-dependent, but it will always be a |
| 570 | * subclass of {@link IOException}. |
| 571 | * |
| 572 | * |
| 573 | * @param cmdarray array containing the command to call and |
| 574 | * its arguments. |
| 575 | * |
| 576 | * @param envp array of strings, each element of which |
| 577 | * has environment variable settings in the format |
| 578 | * <i>name</i>=<i>value</i>, or |
| 579 | * <tt>null</tt> if the subprocess should inherit |
| 580 | * the environment of the current process. |
| 581 | * |
| 582 | * @param dir the working directory of the subprocess, or |
| 583 | * <tt>null</tt> if the subprocess should inherit |
| 584 | * the working directory of the current process. |
| 585 | * |
| 586 | * @return A new {@link Process} object for managing the subprocess |
| 587 | * |
| 588 | * @throws SecurityException |
| 589 | * If a security manager exists and its |
| 590 | * {@link SecurityManager#checkExec checkExec} |
| 591 | * method doesn't allow creation of the subprocess |
| 592 | * |
| 593 | * @throws IOException |
| 594 | * If an I/O error occurs |
| 595 | * |
| 596 | * @throws NullPointerException |
| 597 | * If <code>cmdarray</code> is <code>null</code>, |
| 598 | * or one of the elements of <code>cmdarray</code> is <code>null</code>, |
| 599 | * or one of the elements of <code>envp</code> is <code>null</code> |
| 600 | * |
| 601 | * @throws IndexOutOfBoundsException |
| 602 | * If <code>cmdarray</code> is an empty array |
| 603 | * (has length <code>0</code>) |
| 604 | * |
| 605 | * @see ProcessBuilder |
| 606 | * @since 1.3 |
| 607 | */ |
| 608 | public Process exec(String[] cmdarray, String[] envp, File dir) |
| 609 | throws IOException { |
| 610 | return new ProcessBuilder(cmdarray) |
| 611 | .environment(envp) |
| 612 | .directory(dir) |
| 613 | .start(); |
| 614 | } |
| 615 | |
| 616 | /** |
| 617 | * Returns the number of processors available to the Java virtual machine. |
| 618 | * |
| 619 | * <p> This value may change during a particular invocation of the virtual |
| 620 | * machine. Applications that are sensitive to the number of available |
| 621 | * processors should therefore occasionally poll this property and adjust |
| 622 | * their resource usage appropriately. </p> |
| 623 | * |
| 624 | * @return the maximum number of processors available to the virtual |
| 625 | * machine; never smaller than one |
| 626 | * @since 1.4 |
| 627 | */ |
| 628 | public native int availableProcessors(); |
| 629 | |
| 630 | /** |
| 631 | * Returns the amount of free memory in the Java Virtual Machine. |
| 632 | * Calling the |
| 633 | * <code>gc</code> method may result in increasing the value returned |
| 634 | * by <code>freeMemory.</code> |
| 635 | * |
| 636 | * @return an approximation to the total amount of memory currently |
| 637 | * available for future allocated objects, measured in bytes. |
| 638 | */ |
| 639 | public native long freeMemory(); |
| 640 | |
| 641 | /** |
| 642 | * Returns the total amount of memory in the Java virtual machine. |
| 643 | * The value returned by this method may vary over time, depending on |
| 644 | * the host environment. |
| 645 | * <p> |
| 646 | * Note that the amount of memory required to hold an object of any |
| 647 | * given type may be implementation-dependent. |
| 648 | * |
| 649 | * @return the total amount of memory currently available for current |
| 650 | * and future objects, measured in bytes. |
| 651 | */ |
| 652 | public native long totalMemory(); |
| 653 | |
| 654 | /** |
| 655 | * Returns the maximum amount of memory that the Java virtual machine will |
| 656 | * attempt to use. If there is no inherent limit then the value {@link |
| 657 | * java.lang.Long#MAX_VALUE} will be returned. </p> |
| 658 | * |
| 659 | * @return the maximum amount of memory that the virtual machine will |
| 660 | * attempt to use, measured in bytes |
| 661 | * @since 1.4 |
| 662 | */ |
| 663 | public native long maxMemory(); |
| 664 | |
| 665 | /** |
| 666 | * Runs the garbage collector. |
| 667 | * Calling this method suggests that the Java virtual machine expend |
| 668 | * effort toward recycling unused objects in order to make the memory |
| 669 | * they currently occupy available for quick reuse. When control |
| 670 | * returns from the method call, the virtual machine has made |
| 671 | * its best effort to recycle all discarded objects. |
| 672 | * <p> |
| 673 | * The name <code>gc</code> stands for "garbage |
| 674 | * collector". The virtual machine performs this recycling |
| 675 | * process automatically as needed, in a separate thread, even if the |
| 676 | * <code>gc</code> method is not invoked explicitly. |
| 677 | * <p> |
| 678 | * The method {@link System#gc()} is the conventional and convenient |
| 679 | * means of invoking this method. |
| 680 | */ |
| 681 | public native void gc(); |
| 682 | |
| 683 | /* Wormhole for calling java.lang.ref.Finalizer.runFinalization */ |
| 684 | private static native void runFinalization0(); |
| 685 | |
| 686 | /** |
| 687 | * Runs the finalization methods of any objects pending finalization. |
| 688 | * Calling this method suggests that the Java virtual machine expend |
| 689 | * effort toward running the <code>finalize</code> methods of objects |
| 690 | * that have been found to be discarded but whose <code>finalize</code> |
| 691 | * methods have not yet been run. When control returns from the |
| 692 | * method call, the virtual machine has made a best effort to |
| 693 | * complete all outstanding finalizations. |
| 694 | * <p> |
| 695 | * The virtual machine performs the finalization process |
| 696 | * automatically as needed, in a separate thread, if the |
| 697 | * <code>runFinalization</code> method is not invoked explicitly. |
| 698 | * <p> |
| 699 | * The method {@link System#runFinalization()} is the conventional |
| 700 | * and convenient means of invoking this method. |
| 701 | * |
| 702 | * @see java.lang.Object#finalize() |
| 703 | */ |
| 704 | public void runFinalization() { |
| 705 | runFinalization0(); |
| 706 | } |
| 707 | |
| 708 | /** |
| 709 | * Enables/Disables tracing of instructions. |
| 710 | * If the <code>boolean</code> argument is <code>true</code>, this |
| 711 | * method suggests that the Java virtual machine emit debugging |
| 712 | * information for each instruction in the virtual machine as it |
| 713 | * is executed. The format of this information, and the file or other |
| 714 | * output stream to which it is emitted, depends on the host environment. |
| 715 | * The virtual machine may ignore this request if it does not support |
| 716 | * this feature. The destination of the trace output is system |
| 717 | * dependent. |
| 718 | * <p> |
| 719 | * If the <code>boolean</code> argument is <code>false</code>, this |
| 720 | * method causes the virtual machine to stop performing the |
| 721 | * detailed instruction trace it is performing. |
| 722 | * |
| 723 | * @param on <code>true</code> to enable instruction tracing; |
| 724 | * <code>false</code> to disable this feature. |
| 725 | */ |
| 726 | public native void traceInstructions(boolean on); |
| 727 | |
| 728 | /** |
| 729 | * Enables/Disables tracing of method calls. |
| 730 | * If the <code>boolean</code> argument is <code>true</code>, this |
| 731 | * method suggests that the Java virtual machine emit debugging |
| 732 | * information for each method in the virtual machine as it is |
| 733 | * called. The format of this information, and the file or other output |
| 734 | * stream to which it is emitted, depends on the host environment. The |
| 735 | * virtual machine may ignore this request if it does not support |
| 736 | * this feature. |
| 737 | * <p> |
| 738 | * Calling this method with argument false suggests that the |
| 739 | * virtual machine cease emitting per-call debugging information. |
| 740 | * |
| 741 | * @param on <code>true</code> to enable instruction tracing; |
| 742 | * <code>false</code> to disable this feature. |
| 743 | */ |
| 744 | public native void traceMethodCalls(boolean on); |
| 745 | |
| 746 | /** |
| 747 | * Loads the specified filename as a dynamic library. The filename |
| 748 | * argument must be a complete path name, |
| 749 | * (for example |
| 750 | * <code>Runtime.getRuntime().load("/home/avh/lib/libX11.so");</code>). |
| 751 | * <p> |
| 752 | * First, if there is a security manager, its <code>checkLink</code> |
| 753 | * method is called with the <code>filename</code> as its argument. |
| 754 | * This may result in a security exception. |
| 755 | * <p> |
| 756 | * This is similar to the method {@link #loadLibrary(String)}, but it |
| 757 | * accepts a general file name as an argument rather than just a library |
| 758 | * name, allowing any file of native code to be loaded. |
| 759 | * <p> |
| 760 | * The method {@link System#load(String)} is the conventional and |
| 761 | * convenient means of invoking this method. |
| 762 | * |
| 763 | * @param filename the file to load. |
| 764 | * @exception SecurityException if a security manager exists and its |
| 765 | * <code>checkLink</code> method doesn't allow |
| 766 | * loading of the specified dynamic library |
| 767 | * @exception UnsatisfiedLinkError if the file does not exist. |
| 768 | * @exception NullPointerException if <code>filename</code> is |
| 769 | * <code>null</code> |
| 770 | * @see java.lang.Runtime#getRuntime() |
| 771 | * @see java.lang.SecurityException |
| 772 | * @see java.lang.SecurityManager#checkLink(java.lang.String) |
| 773 | */ |
| 774 | public void load(String filename) { |
| 775 | load0(System.getCallerClass(), filename); |
| 776 | } |
| 777 | |
| 778 | synchronized void load0(Class fromClass, String filename) { |
| 779 | SecurityManager security = System.getSecurityManager(); |
| 780 | if (security != null) { |
| 781 | security.checkLink(filename); |
| 782 | } |
| 783 | if (!(new File(filename).isAbsolute())) { |
| 784 | throw new UnsatisfiedLinkError( |
| 785 | "Expecting an absolute path of the library: " + filename); |
| 786 | } |
| 787 | ClassLoader.loadLibrary(fromClass, filename, true); |
| 788 | } |
| 789 | |
| 790 | /** |
| 791 | * Loads the dynamic library with the specified library name. |
| 792 | * A file containing native code is loaded from the local file system |
| 793 | * from a place where library files are conventionally obtained. The |
| 794 | * details of this process are implementation-dependent. The |
| 795 | * mapping from a library name to a specific filename is done in a |
| 796 | * system-specific manner. |
| 797 | * <p> |
| 798 | * First, if there is a security manager, its <code>checkLink</code> |
| 799 | * method is called with the <code>libname</code> as its argument. |
| 800 | * This may result in a security exception. |
| 801 | * <p> |
| 802 | * The method {@link System#loadLibrary(String)} is the conventional |
| 803 | * and convenient means of invoking this method. If native |
| 804 | * methods are to be used in the implementation of a class, a standard |
| 805 | * strategy is to put the native code in a library file (call it |
| 806 | * <code>LibFile</code>) and then to put a static initializer: |
| 807 | * <blockquote><pre> |
| 808 | * static { System.loadLibrary("LibFile"); } |
| 809 | * </pre></blockquote> |
| 810 | * within the class declaration. When the class is loaded and |
| 811 | * initialized, the necessary native code implementation for the native |
| 812 | * methods will then be loaded as well. |
| 813 | * <p> |
| 814 | * If this method is called more than once with the same library |
| 815 | * name, the second and subsequent calls are ignored. |
| 816 | * |
| 817 | * @param libname the name of the library. |
| 818 | * @exception SecurityException if a security manager exists and its |
| 819 | * <code>checkLink</code> method doesn't allow |
| 820 | * loading of the specified dynamic library |
| 821 | * @exception UnsatisfiedLinkError if the library does not exist. |
| 822 | * @exception NullPointerException if <code>libname</code> is |
| 823 | * <code>null</code> |
| 824 | * @see java.lang.SecurityException |
| 825 | * @see java.lang.SecurityManager#checkLink(java.lang.String) |
| 826 | */ |
| 827 | public void loadLibrary(String libname) { |
| 828 | loadLibrary0(System.getCallerClass(), libname); |
| 829 | } |
| 830 | |
| 831 | synchronized void loadLibrary0(Class fromClass, String libname) { |
| 832 | SecurityManager security = System.getSecurityManager(); |
| 833 | if (security != null) { |
| 834 | security.checkLink(libname); |
| 835 | } |
| 836 | if (libname.indexOf((int)File.separatorChar) != -1) { |
| 837 | throw new UnsatisfiedLinkError( |
| 838 | "Directory separator should not appear in library name: " + libname); |
| 839 | } |
| 840 | ClassLoader.loadLibrary(fromClass, libname, false); |
| 841 | } |
| 842 | |
| 843 | /** |
| 844 | * Creates a localized version of an input stream. This method takes |
| 845 | * an <code>InputStream</code> and returns an <code>InputStream</code> |
| 846 | * equivalent to the argument in all respects except that it is |
| 847 | * localized: as characters in the local character set are read from |
| 848 | * the stream, they are automatically converted from the local |
| 849 | * character set to Unicode. |
| 850 | * <p> |
| 851 | * If the argument is already a localized stream, it may be returned |
| 852 | * as the result. |
| 853 | * |
| 854 | * @param in InputStream to localize |
| 855 | * @return a localized input stream |
| 856 | * @see java.io.InputStream |
| 857 | * @see java.io.BufferedReader#BufferedReader(java.io.Reader) |
| 858 | * @see java.io.InputStreamReader#InputStreamReader(java.io.InputStream) |
| 859 | * @deprecated As of JDK 1.1, the preferred way to translate a byte |
| 860 | * stream in the local encoding into a character stream in Unicode is via |
| 861 | * the <code>InputStreamReader</code> and <code>BufferedReader</code> |
| 862 | * classes. |
| 863 | */ |
| 864 | @Deprecated |
| 865 | public InputStream getLocalizedInputStream(InputStream in) { |
| 866 | return in; |
| 867 | } |
| 868 | |
| 869 | /** |
| 870 | * Creates a localized version of an output stream. This method |
| 871 | * takes an <code>OutputStream</code> and returns an |
| 872 | * <code>OutputStream</code> equivalent to the argument in all respects |
| 873 | * except that it is localized: as Unicode characters are written to |
| 874 | * the stream, they are automatically converted to the local |
| 875 | * character set. |
| 876 | * <p> |
| 877 | * If the argument is already a localized stream, it may be returned |
| 878 | * as the result. |
| 879 | * |
| 880 | * @deprecated As of JDK 1.1, the preferred way to translate a |
| 881 | * Unicode character stream into a byte stream in the local encoding is via |
| 882 | * the <code>OutputStreamWriter</code>, <code>BufferedWriter</code>, and |
| 883 | * <code>PrintWriter</code> classes. |
| 884 | * |
| 885 | * @param out OutputStream to localize |
| 886 | * @return a localized output stream |
| 887 | * @see java.io.OutputStream |
| 888 | * @see java.io.BufferedWriter#BufferedWriter(java.io.Writer) |
| 889 | * @see java.io.OutputStreamWriter#OutputStreamWriter(java.io.OutputStream) |
| 890 | * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream) |
| 891 | */ |
| 892 | @Deprecated |
| 893 | public OutputStream getLocalizedOutputStream(OutputStream out) { |
| 894 | return out; |
| 895 | } |
| 896 | |
| 897 | } |